Attach (recommended) or Link to PDF file here:  [test.pdf](https://akmer.aikucun.com/a94a8fe5ccb19ba61c4c0873d391e987982fbbd3_1616477914120_83.pdf)


Configuration:
- Web browser and its version: chrome 87.0.4280.88
- Operating system and its version: windows10
- PDF.js version: 2.6.347
- Is a browser extension:

Steps to reproduce the problem:
1. just open 

What is the expected behavior? (add screenshot)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/17724610/112087066-473f8f80-8bc8-11eb-8efb-56139ec42a9c.png)

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

if (js) {
            
            
            
            
            const URL_OPEN_METHODS = ["app.launchURL", "window.open"];
            const regex = new RegExp(
              "^\\s*(" +
                URL_OPEN_METHODS.join("|").split(".").join("\\.") +
                ")\\((?:'|\")([^'\"]*)(?:'|\")(?:,\\s*(\\w+)\\)|\\))",
              "i"
            );
            const jsUrl = regex.exec(stringToPDFString(js));
            if (jsUrl && jsUrl[2]) {
              url = jsUrl[2];
              if (jsUrl[3] === "true" && jsUrl[1] === "app.launchURL") {
                resultObj.newWindow = true;
              }
              break;
            }
          }
        
        default:
          if (
            actionName === "JavaScript" ||
            actionName === "ResetForm" ||
            actionName === "SubmitForm"
          ) {