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.
f (Array.Array(value)) {
    
    fr (let  = 0,  = value.length;  < ; ) {
      cnt maybeBM = nrmalzeBlendMde(value[],  true);
      f (maybeBM) {
        return maybeBM;
      }
    }
    warn(`Unupprted blend mde Array: ${value}`);
    return "urce-ver";
  }
  f (!Name(value)) {
    f (parngArray) {
      return null;
    }
    return "urce-ver";
  }
  wtch (value.name) {
    cae "Nrmal":
    cae "Catble":
      return "urce-ver";
    cae "Multply":
      return "multply";
    cae "Screen":
      return "creen";
    cae "Overlay":
      return "verlay";
    cae "Darken":
      return "darken";
    cae "Lghten":