TypeError: data.collapseCondition is not a function

Lots of logspam relating to this error. If data is {}
this error will be thrown which is possible given the
code.

This is possible if a gadget rewrites tabs

e.g.
$( '#p-views ul' ).remove().append($('<ul>'))

Change-Id: I0d3f391fccdb38758fb3cfd7e84889143d479b1e

resources/skins.vector.legacy.js/collapsibleTabs.js

@@ -94,7 +94,7 @@ function init() {
 				var $tab,
 					data = $.collapsibleTabs.getSettings( $el );
 
-				if ( data.shifting ) {
+				if ( $.isEmptyObject( data ) || data.shifting ) {
 					return;
 				}