Issue webcompat#1167. Check optional os and browser fields inside of checkForm.

Author: Mike Taylor

webcompat/static/js/lib/bugform.js

@@ -223,12 +223,15 @@ function BugForm() {
       this.checkURLValidity();
       this.checkProblemTypeValidity();
       this.checkImageTypeValidity();
-      this.checkOptionalNonEmpty();
       // and open the form, if it's not already open
       if (!this.reportButton.hasClass('is-open')) {
         this.reportButton.click();
       }
     }
+    // Make sure we only do this if the inputs exist on the page
+    if (this.browserField.length || this.osField.length) {
+      this.checkOptionalNonEmpty();
+    }
   };
 
   /* makeInvalid can take an {altHelp: true} options argument to select