Fix: When saving Layout, change "mode = VIEWING" only after successful name checks (montage.js)

web/skins/classic/views/js/montage.js

@@ -383,8 +383,6 @@ function edit_layout(button) {
 } // end function edit_layout
 
 function save_layout(button) {
-  mode = VIEWING;
-
   const form = button.form;
   let name = form.elements['Name'].value;
   const layout = layouts[form.zmMontageLayout.value];
@@ -403,6 +401,8 @@ function save_layout(button) {
     return;
   }
 
+  mode = VIEWING;
+
   var Positions = {};
   Positions['gridStack'] = objGridStack.save(false, false);
   Positions['monitorStatusPositon'] = $j('#monitorStatusPositon').val(); //Not yet used when reading Layout