update hint for mouse double-click

Author: selectiveduplicate

capplets/keybindings/mate-keybinding-properties.ui

@@ -336,7 +336,7 @@
                         <property name="visible">True</property>
                         <property name="can_focus">False</property>
                         <property name="halign">start</property>
-                        <property name="label" translatable="yes">To edit a shortcut key, click on the corresponding row and type a new key combination, or press backspace to clear.</property>
+                        <property name="label" translatable="yes">To edit a shortcut key, double-click on the corresponding row and type a new key combination, or press backspace to clear.</property>
                         <property name="wrap">True</property>
                       </object>
                       <packing>