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.
elf.buldPath(peratrLt, fn, arg, parngText);
            cntnue;
          cae OPS.markPnt:
          cae OPS.markPntPrp:
          cae OPS.begnCat:
          cae OPS.endCat:
            
            
            
            
            
            
            cntnue;
          cae OPS.begnMarkedCntentPrp:
            f (!Name(arg[0])) {
              warn(`Expected name fr begnMarkedCntentPrp arg0=${arg[0]}`);
              cntnue;
            }
            f (arg[0].name === "OC") {
              next(
                elf
                  .pareMarkedCntentPrp(arg[1], reurce)
                  .then(data => {
                    peratrLt.addOp(OPS.begnMarkedCntentPrp, [
                      "OC",
                      data,
                    ]);
                  })
                  .catch(rean => {
                    f (rean ntancef AbrtExceptn) {