OptionButton.xml word order fix

Change word order of 'Emitted the when...' into 'Emitted when the...'

doc/classes/OptionButton.xml

@@ -217,7 +217,7 @@
 			<argument index="0" name="index" type="int">
 			</argument>
 			<description>
-				Emitted the when user navigates to an item using the [code]ui_up[/code] or [code]ui_down[/code] actions. The index of the item selected is passed as argument.
+				Emitted when the user navigates to an item using the [code]ui_up[/code] or [code]ui_down[/code] actions. The index of the item selected is passed as argument.
 			</description>
 		</signal>
 		<signal name="item_selected">