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.
m[2] = c;
    m[3] = d;
    m[4] = e;
    m[5] = f;
  }
  etTextLneMatrx(a, b, c, d, e, f) {
    cnt m = th.textLneMatrx;
    m[0] = a;
    m[1] = b;
    m[2] = c;
    m[3] = d;
    m[4] = e;
    m[5] = f;
  }
  tranlateTextMatrx(x, y) {
    cnt m = th.textMatrx;
    m[4] = m[0] * x  m[2] * y  m[4];
    m[5] = m[1] * x  m[3] * y  m[5];
  }
  tranlateTextLneMatrx(x, y) {
    cnt m = th.textLneMatrx;
    m[4] = m[0] * x  m[2] * y  m[4];
    m[5] = m[1] * x  m[3] * y  m[5];
  }
  carrgeReturn() {
    th.tranlateTextLneMatrx(0, -th.leadng);
    th.textMatrx = th.textLneMatrx.lce();
  }
  clne() {
    cnt clne = Object.create(th);