rustdoc: Prevent '/' from showing the help dialog

Only '?' should do that.

Fixes rust-lang#24289.

Author: barosl

src/librustdoc/html/static/main.js

@@ -78,9 +78,11 @@
             return;
         }
 
-        if (e.which === 191 && $('#help').hasClass('hidden')) { // question mark
-            e.preventDefault();
-            $('#help').removeClass('hidden');
+        if (e.which === 191) { // question mark
+            if (e.shiftKey && $('#help').hasClass('hidden')) {
+                e.preventDefault();
+                $('#help').removeClass('hidden');
+            }
         } else if (e.which === 27) { // esc
             if (!$('#help').hasClass('hidden')) {
                 e.preventDefault();