Fix the toggle case shortcut key combination. Fixes #3999

docs/en_US/release_notes_4_15.rst

@@ -23,6 +23,7 @@ Bug fixes
 | `Issue #3789 <https://redmine.postgresql.org/issues/3789>`_ -  Ensure context menus never get hidden below the menu bar.
 | `Issue #3913 <https://redmine.postgresql.org/issues/3913>`_ -  Ensure the correct "running at" agent is shown when a pgAgent job is executing.
 | `Issue #3915 <https://redmine.postgresql.org/issues/3915>`_ -  Fix an issue in the Query Tool where shortcut keys could be ignored following a query error.
+| `Issue #3999 <https://redmine.postgresql.org/issues/3999>`_ -  Fix the toggle case shortcut key combination.
 | `Issue #4191 <https://redmine.postgresql.org/issues/4191>`_ -  Ensure comments are shown in reverse engineered SQL for table partitions.
 | `Issue #4242 <https://redmine.postgresql.org/issues/4242>`_ -  Handle NULL values appropriately when sorting backgrid tables.
 | `Issue #4341 <https://redmine.postgresql.org/issues/4341>`_ -  Give appropriate error messages when the user tries to use an blank master password.

web/pgadmin/tools/sqleditor/utils/query_tool_preferences.py

@@ -641,7 +641,7 @@ def RegisterQueryToolPreferences(self):
             'shift': True,
             'control': True,
             'key': {
-                'key_code': 91,
+                'key_code': 85,
                 'char': 'u'
             }
         },