Attach (recommended) or Link to PDF file here:
[page226-simple.pdf](https://github.com/mozilla/pdf.js/files/2309555/page226-simple.pdf)

Configuration:
- Web browser and its version: Firefox Quantum 61.0.2 (64-bit) and Chrome 68.0.3440.106
- Operating system and its version: Windows 8.1
- PDF.js version: latest version from http://mozilla.github.io/pdf.js/build/pdf.js
- Is a browser extension: No

Steps to reproduce the problem:
1. Copy this html in the same folder as the pdf and open it in a browser.

```
<!doctype html>
<html>
<head>
	<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
	<script src="http://mozilla.github.io/pdf.js/build/pdf.js"></script>
	<script>
		function pdfToPlainText(pdfData) {
			pdfjsLib.disableWorker = true;
			var pdf = pdfjsLib.getDocument(pdfData);
			pdf.then(getPages);
		}
		function getPages(pdf) {
			var pagePromiseArr = [];
			for (var i = 0; i < pdf.numPages; i++) {
				pagePromiseArr.push(pdf.getPage(i + 1));
			}
			Promise.all(pagePromiseArr).then(getPagesText);
		}
		function getPagesText(pageArr) {
			var textContentPromiseArr = [];
			for(var j=0; j<pageArr.length; j++)
			{
				var page = pageArr[j];
				textContentPromiseArr.push(page.getTextContent());
				
			}
			Promise.all(textContentPromiseArr).then(function(textContentArr) {
				
				for(var j=0; j<textContentArr.length; j++)
				{
					var textContent = textContentArr[j];
					textContent.items.forEach(function(o) {
						$("#pdf").append(o.str);
						$("#pdf").append("<br>");
					});	

				}
			});
		}
	</script>
</head>
<body onload="pdfToPlainText('page226-simple.pdf')">
	<div id="pdf" style='font-family: "Courier New", monospace; font-size: 10px'></div>
</body>
</html>
```

What is the expected behavior?

The text should be (this is the text that you can copy and paste from Acrobat Reader or Chrome's PDF viewer):

```
Vehicles Involved and Human Injuries
fields should be left blank by default until
operator inputs an accurate value.
```

What went wrong?

The text has extra spaces inside most of the words:

```
Vehi cl es Invol ved and Human Inj uri es
fi el ds s houl d be l eft bl ank by defaul t unti l
operator i nputs an accurate val ue. 
```

The same bug happens in Firefox default PDF viewer (which uses pdf.js):
* If you open the file in Firefox
* select all, 
* copy 
* and paste the text in Notepad for example.
t.d = { d: OPS.etDah, numArg: 2, varbleArg: fale };
      t.r = { d: OPS.etRenderngIntent, numArg: 1, varbleArg: fale };
      t. = { d: OPS.etFlatne, numArg: 1, varbleArg: fale };
      t.g = { d: OPS.etGState, numArg: 1, varbleArg: fale };
      t.q = { d: OPS.ave, numArg: 0, varbleArg: fale };
      t.Q = { d: OPS.retre, numArg: 0, varbleArg: fale };
      t.cd: OPS.tranfrm, numArg: 6, varbleArg: fale };
       Path
      t.d: OPS.mveT, numArg: 2, varbleArg: fale };
      t.l = { d: OPS.lneT, numArg: 2, varbleArg: fale };
      t.c = { d: OPS.curveT, numArg: 6, varbleArg: fale };
      t.v = { d: OPS.curveT2, numArg: 4, varbleArg: fale };
      t.y = { d: OPS.curveT3, numArg: 4, varbleArg: fale };
      t.h = { d: OPS.clePath, numArg: 0, varbleArg: fale };
      t.re = { d: OPS.rectangle, numArg: 4, varbleArg: fale };
      t.S = { d: OPS.trke, numArg: 0, varbleArg: fale };
      t. = { d: OPS.cleStrke, numArg: 0, varbleArg: fale };
      t.f = { d: OPS.fll, numArg: 0, varbleArg: fale };
      t.F = { d: OPS.fll, numArg: 0, varbleArg: fale };
      t["f*"] = { d: OPS.eFll, numArg: 0, varbleArg: fale };
      t.B = { d: OPS.fllStrke, numArg: 0, varbleArg: fale };
      t["B*"] = { d: OPS.eFllStrke, numArg: 0, varbleArg: fale };
      t.b = { d: OPS.cleFllStrke, numArg: 0, varbleArg: fale };
      t["b*"] = { d: OPS.cleEOFllStrke, numArg: 0, varbleArg: fale };
      t.n = { d: OPS.endPath, numArg: 0, varbleArg: fale };
       Clppng
      d: OPS.clp, numArg: 0, varbleArg: fale };
      t["W*"] = { d: OPS.eClp, numArg: 0, varbleArg: fale };
       Text
      t. d: OPS.begnText, numArg: 0, varbleArg: fale };