Attach (recommended) or Link to PDF file here:
[Hong Kong Aircraft Engineering Company Limited_1511417616.1 2.pdf](https://github.com/mozilla/pdf.js/files/1539395/Hong.Kong.Aircraft.Engineering.Company.Limited_1511417616.1.2.pdf)


Configuration:
- Web browser and its version: Chrome: 63 
- Operating system and its version: windows and macOs
- PDF.js version: 2.0.185
- Is a browser extension: No

Steps to reproduce the problem:
1. Upload the above PDF and search for "article 1"
2. PDF.js showing only **2** match But actually **4** times available.   

What is the expected behavior? (add screenshot)

![screen shot 2017-12-07 at 7](https://user-images.githubusercontent.com/6101789/33720106-ed404576-db88-11e7-9c19-cf6aea74e9f3.png)



What went wrong? (add screenshot)

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):

let totalPages = matchesPerPage.length;
    for (let i = totalPages - 1; i >= 0; i--) {
      if (matchesPerPage[i] > 0) {
        totalPages = i + 1;
        break;
      }
    }
    const totalMatches = matchesPerPage.reduce((a, b) => {
      return a + b;
    });
    eventBus.on(
      "updatefindmatchescount",
      function onUpdateFindMatchesCount(evt) {
        if (pdfFindController.pageMatches.length !== totalPages) {
          return;
        }
        eventBus.off("updatefindmatchescount", onUpdateFindMatchesCount);
        expect(evt.matchesCount.total).toBe(totalMatches);
        for (let i = 0; i < totalPages; i++) {
          expect(pdfFindController.pageMatches[i].length).toEqual(
            matchesPerPage[i]
          );
        }
        expect(pdfFindController.selected.pageIdx).toEqual(
          selectedMatch.pageIndex
        );
        expect(pdfFindController.selected.matchIdx).toEqual(
          selectedMatch.matchIndex