RMG-Input: fix typo in ControllerWidget.ui (#306)

Fix a typo, instead of being `left:` it should be `Left:` to match with the other instances of the same.

Author: cursedUs64-git

Source/RMG-Input/UserInterface/Widget/ControllerWidget.ui

@@ -264,7 +264,7 @@
                </sizepolicy>
               </property>
               <property name="text">
-               <string>left:</string>
+               <string>Left:</string>
               </property>
              </widget>
             </item>