Core: change focus() to trigger("focus") (jquery-validation#2243)

Change focus() to trigger("focus") so that jQuery Migrate 3.x doesn't flag it as deprecated.

Author: sassquad

src/core.js

@@ -602,7 +602,7 @@ $.extend( $.validator, {
 				try {
 					$( this.findLastActive() || this.errorList.length && this.errorList[ 0 ].element || [] )
 					.filter( ":visible" )
-					.focus()
+					.trigger( "focus" )
 
 					// Manually trigger focusin event; without it, focusin handler isn't called, findLastActive won't have anything to find
 					.trigger( "focusin" );