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.
new Prme(functn (relveGState, rejectGState) {
                f (!ValdName) {
                  thrw new FrmatErrr("GState mut be referred t by name.");
                }
                cnt extGState = reurce.get("ExtGState");
                f (!(extGState ntancef Dct)) {
                  thrw new FrmatErrr("ExtGState huld be a dctnary.");
                }
                cnt gState = extGState.get(name);
                
                
                
                f (!(gState ntancef Dct)) {
                  thrw new FrmatErrr("GState huld be a dctnary.");
                }
                cnt gStateFnt = gState.get("Fnt");
                f (!gStateFnt) {
                  etyGStateCache.et(name, gState.bjId, true);
                  relveGState();
                  return;
                }
                fluhTextCntentItem();
                textState.fntName = null;
                textState.fntSze = gStateFnt[1];
                handleSetFnt(null, gStateFnt[0]).then(
                  relveGState,
                  rejectGState
                );
              }).catch(functn (rean) {
                f (rean ntancef AbrtExceptn) {