Attach (recommended) or Link to PDF file here:
https://bitcoin.org/bitcoin.pdf

Configuration:
- Web browser and its version: all
- Operating system and its version: all
- PDF.js version: tested with 2.9.11, but most likely all versions
- Is a browser extension: no

Steps to reproduce the problem:
1. Type "a purely" (single space between "a" and "purely") - doesn't find anything
2. Type "a  purely" (two spaces between "a" and "purely") - finds the phrase

Sometimes even 3 spaces are necessary.

What is the expected behavior? (add screenshot)
![Screenshot from 2021-04-08 13-00-03](https://user-images.githubusercontent.com/6362989/114008903-57639a00-986b-11eb-903a-92bbebbd922b.png)

What went wrong? (add screenshot)
![Screenshot from 2021-04-08 13-01-53](https://user-images.githubusercontent.com/6362989/114008810-44e96080-986b-11eb-8232-f58a62ed7899.png)

This affects many PDFs because justify alignment is common enough.
let shouldScaleText = false;
  if (
    geom.str.length > 1 ||
    (task._enhanceTextSelection && AllWhitespaceRegexp.test(geom.str))
  ) {
    shouldScaleText = true;
  } else if (geom.transform[0] !== geom.transform[3]) {
    const absScaleX = Math.abs(geom.transform[0]),
      absScaleY = Math.abs(geom.transform[3]);
    
    
    if (
      absScaleX !== absScaleY &&
      Math.max(absScaleX, absScaleY) / Math.min(absScaleX, absScaleY) > 1.5
    ) {
      shouldScaleText = true;
    }
  }
  if (shouldScaleText) {
    if (style.vertical) {
      textDivProperties.canvasWidth = geom.height * task._viewport.scale;
    } else {
      textDivProperties.canvasWidth = geom.width * task._viewport.scale;
    }
  }
  task._textDivProperties.set(textDiv, textDivProperties);
  if (task._textContentStream) {
    task._layoutText(textDiv);