editor: fix variable shadowing in let causing use before declaration

app/static/scripts/editor.js

@@ -25,14 +25,14 @@ ta.addEventListener('keydown', function(e) {
         e.target.selectionEnd = start + 1;
     }
     if (e.ctrlKey && keyCode == 13) {
-        let e = e.target;
-        while(! (e instanceof HTMLFormElement)) {
-            e = e.parentNode;
+        let t = e.target;
+        while(! (t instanceof HTMLFormElement)) {
+            t = t.parentNode;
         }
         try {
-            e.submit();
+            t.submit();
         } catch(exception) {
-            e.submit.click();
+            t.submit.click();
         }
     }
 });