mw.ViewPageTarget.init: Add missing 'return target'

Follows-up I002322beaae. I had this in the local patch but got
lost in rebasing. The missing return statement caused an uncaught
error when clicking section edit links as it was not forwarding
the return value.

Change-Id: I66b6a789f7182a4446122e94f19cfdb324f8d675

modules/ve-mw/init/targets/ve.init.mw.ViewPageTarget.init.js

@@ -403,6 +403,7 @@
 
 			targetPromise = getTarget().then( function ( target ) {
 				target.saveEditSection( $( e.target ).closest( 'h1, h2, h3, h4, h5, h6' ).get( 0 ) );
+				return target;
 			} );
 			activateTarget( targetPromise );
 		}