Fix Ctrl-Enter shortcut for issues (#10986)

The js-quick-submit class needs to be applied to SimpleMDE's input
field, which is currently only done for wiki pages.

Fixes #10937

Co-authored-by: Lauris BH <lauris@nix.lv>
Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: guillep2k <18600385+guillep2k@users.noreply.github.com>

web_src/js/index.js

@@ -1525,6 +1525,7 @@ function setSimpleMDE($editArea) {
       },
     ]
   });
+  $(simpleMDEditor.codemirror.getInputField()).addClass('js-quick-submit');
 
   return true;
 }
@@ -1556,6 +1557,7 @@ function setCommentSimpleMDE($editArea) {
       },
     ]
   });
+  $(simplemde.codemirror.getInputField()).addClass('js-quick-submit');
   simplemde.codemirror.setOption('extraKeys', {
     Enter: () => {
       if (!(issuesTribute.isActive || emojiTribute.isActive)) {