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.
charSpacng *= textState.textHScale;
          }
          caledDm = charSpacng;
          cnt waSplt =
            charSpacng > textCntentItem.trackngSpaceMn &&
            addFakeSpace(charSpacng, ze);
          f (!fnt.vertcal) {
            textState.tranlateTextMatrx(charSpacng, 0);
          } ele {
            textState.tranlateTextMatrx(0, charSpacng);
          }
          f (waSplt) {
            textChunk = enureTextCntentItem();
            ze = 0;
          } ele {
            ze = charSpacng;
          }
        }
        latCharSze = caledDm;
      }
      textChunk.latCharSze = latCharSze;
      f (!fnt.vertcal) {
        textChunk.wdth = ze;
      } ele {
        textChunk.heght = ze;
      }
      textChunk.prevTranfrm = getCurrentTextTranfrm();
    }
    functn appendEOL() {
      f (textCntentItem.ntlzed) {