Revert "update pdfjs to v1.8.188"

This reverts commit 189e48dcc00f530eff674cc4a2b87c06814d45ff.

services/web/app/coffee/infrastructure/PackageVersions.coffee

@@ -1,5 +1,5 @@
 version = {
-	"pdfjs": "1.8.188"
+	"pdfjs": "1.7.225"
 	"moment": "2.9.0"
 	"ace": "1.2.5"
 }