gui: Don't trim space on the password field (fixes #3935)

gui/default/syncthing/settings/settingsModalView.html

@@ -91,7 +91,7 @@
           </div>
           <div class="form-group">
             <label translate for="Password">GUI Authentication Password</label>
-            <input id="Password" class="form-control" type="password" ng-model="tmpGUI.password">
+            <input id="Password" class="form-control" type="password" ng-model="tmpGUI.password" ng-trim="false">
           </div>
           <div class="form-group">
             <div class="checkbox">