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.
if (expandDivs) {
        transformBuf.length = 0;
        paddingBuf.length = 0;
        if (divProps.originalTransform) {
          transformBuf.push(divProps.originalTransform);
        }
        if (divProps.paddingTop > 0) {
          paddingBuf.push(`${divProps.paddingTop}px`);
          transformBuf.push(`translateY(${-divProps.paddingTop}px)`);
        } else {
          paddingBuf.push(0);
        }
        if (divProps.paddingRight > 0) {
          paddingBuf.push(`${divProps.paddingRight / divProps.scale}px`);
        } else {
          paddingBuf.push(0);
        }
        if (divProps.paddingBottom > 0) {
          paddingBuf.push(`${divProps.paddingBottom}px`);
        } else {
          paddingBuf.push(0);
        }
        if (divProps.paddingLeft > 0) {
          paddingBuf.push(`${divProps.paddingLeft / divProps.scale}px`);
          transformBuf.push(
            `translateX(${-divProps.paddingLeft / divProps.scale}px)`
          );
        } else {
          paddingBuf.push(0);
        }