made warning dialogs non-blocking

Software-hub/frames/Cart.py

@@ -169,14 +169,14 @@ TODO: Scan RFID card to buy Cart.
             none_message = "API failed to return an item for location {0}.".format(location)
             warning = TimerMessageBox(message=none_message, parent=self)
             warning.setIcon(QtWidgets.QMessageBox.Critical)
-            warning.exec_()
+            warning.show()
             return
         elif 'error' in item.keys():
             # Warn about API error
             api_message = "API returned error '{0}' for location '{1}.".format(item['error'], location)
             warning = TimerMessageBox(message=api_message, parent=self)
             warning.setIcon(QtWidgets.QMessageBox.Critical)
-            warning.exec_()
+            warning.show()
             return
 
     def has_items(self):

Software-hub/frames/Search.py

@@ -305,7 +305,7 @@ Double click an item to add it to the cart."""
             missing_message = "No valid storage position was found for this item. Please contact a workshop board member."
             warning = TimerMessageBox(message=baklager_message, parent=self)
             warning.setIcon(QtWidgets.QMessageBox.Critical)
-            warning.exec_()
+            warning.show()
             return
 
         if lager[lager_choice]['type'] == 'Baklager':
@@ -314,7 +314,7 @@ Double click an item to add it to the cart."""
             baklager_message = "This item is only available at a Baklager. Please contact a board member to buy this item."
             warning = TimerMessageBox(message=baklager_message, parent=self)
             warning.setIcon(QtWidgets.QMessageBox.Critical)
-            warning.exec_()
+            warning.show()
             return
 
         # Add lager_choice