Tabs: Wrap attribute value in quotes when querying. Fixes #8207 - Tab…

…s: Error with href selector.

ui/jquery.ui.tabs.js

@@ -434,7 +434,7 @@ $.widget( "ui.tabs", {
 		// meta-function to give users option to provide a href string instead of a numerical index.
 		// also sanitizes numerical indexes to valid values.
 		if ( typeof index == "string" ) {
-			index = this.anchors.index( this.anchors.filter( "[href$=" + index + "]" ) );
+			index = this.anchors.index( this.anchors.filter( "[href$='" + index + "']" ) );
 		}
 
 		return index;