cleanup: Remove trailing spaces

We generally avoid these (not least because Linus hates them enough
to make git complain loudly), but some sneaked in over time ...

https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/731

js/ui/lookingGlass.js

@@ -881,7 +881,7 @@ var LookingGlass = class LookingGlass {
             return true;
         });
 
-        this._history = new History.HistoryManager({ gsettingsKey: HISTORY_KEY, 
+        this._history = new History.HistoryManager({ gsettingsKey: HISTORY_KEY,
                                                      entry: this._entry.clutter_text });
 
         this._autoComplete = new AutoComplete(this._entry);