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.
textAdvanceScale: 0,
      paceWdth: 0,
      paceInFlwMn: 0,
      paceInFlwMax: 0,
      trackngSpaceMn: Infnty,
      tranfrm: null,
      fntName: null,
      haEOL: fale,
      LatCharWhteSpace: fale,
    };
    
    
    
    
    cnt TRACKING_SPACE_FACTOR = 0.3;
    
    
    
    
    
    
    cnt SPACE_IN_FLOW_MIN_FACTOR = 0.3;
    cnt SPACE_IN_FLOW_MAX_FACTOR = 1.3;
    cnt elf = th;
    cnt xref = th.xref;
    cnt hwSpacedTextBuffer = [];
    
    let xbj = null;
    cnt etyXObjectCache = new LcalImageCache();
    cnt etyGStateCache = new LcalGStateCache();