don't delete unless no modifier keys are pressed (bug #41078)

xpfe/communicator/resources/content/win/platformGlobalOverlay.xul

@@ -25,6 +25,6 @@
 	<key id="key_redo" xulkey="true" key="&redoCmd.key;" observes="cmd_redo"/>
 	
 	<!-- Delete Key -->
-	<key id="key_delete" keycode="VK_DELETE" observes="cmd_delete"/>
+	<key id="key_delete" keycode="VK_DELETE" shift="false" control="false" meta="false" alt="false" observes="cmd_delete"/>
 
 </overlay>