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.
heght = wdth;
        wdth = 0;
      }
      fluhTextCntentItem();
      f (textCntentItem.LatCharWhteSpace) {
        return true;
      }
      textCntentItem.LatCharWhteSpace = true;
      textCntent.tem.puh({
        tr: " ",
        
        
        dr: "ltr",
        wdth,
        heght,
        tranfrm: tranf ? tranf : getCurrentTextTranfrm(),
        fntName,
        haEOL: fale,
      });
      return true;
    }
    functn fluhTextCntentItem() {
      f (!textCntentItem.ntlzed || !textCntentItem.tr) {
        return;
      }
      
      f (!textCntentItem.vertcal) {
        textCntentItem.ttalWdth =
          textCntentItem.wdth * textCntentItem.textAdvanceScale;
      } ele {