Remove unnecessary pageLabel length-check in the viewer
Remove unnecessary pageLabel length-check in the viewer

Given how the pageLabel array is defined, see https://github.com/mozilla/pdf.js/blob/1ab9a6e36e84389775e5f3d6faebdb6b327b8d62/src/core/catalog.js#L627, it shouldn't be necessary to check the length in the viewer.

Snuffleupagus/pdf.js,timvandermeij/pdf.js,nawawi/pdf.js,timvandermeij/pdf.js,showpad/mozilla-pdf.js,mozilla/pdf.js,Shoobx/pdf.js,macroplant/pdf.js,nawawi/pdf.js,Snuffleupagus/pdf.js,mozilla/pdf.js,Snuffleupagus/pdf.js,timvandermeij/pdf.js,showpad/mozilla-pdf.js,Shoobx/pdf.js,mozilla/pdf.js,macroplant/pdf.js,showpad/mozilla-pdf.js,nawawi/pdf.js,macroplant/pdf.js,Shoobx/pdf.js