Fix #12423. Ensure we can .apply() before we try.

I can't think of an uncontrived way to unit test this, it only occurs in IE when a BHO monkeys with the links.

src/event.js

@@ -317,7 +317,7 @@ jQuery.event = {
 			}
 			// Note that this is a bare JS function and not a jQuery handler
 			handle = ontype && cur[ ontype ];
-			if ( handle && jQuery.acceptData( cur ) && handle.apply( cur, data ) === false ) {
+			if ( handle && jQuery.acceptData( cur ) && handle.apply && handle.apply( cur, data ) === false ) {
 				event.preventDefault();
 			}
 		}