Checkboxradio: Fix label handling with jQuery 3.x

Fixes #15006
Closes jquerygh-1720

Author: scottgonzalez

ui/widgets/checkboxradio.js

@@ -69,7 +69,7 @@ $.widget( "ui.checkboxradio", [ $.ui.formResetMixin, {
 
 		// We need to get the label text but this may also need to make sure it does not contain the
 		// input itself.
-		this.label.contents().not( this.element ).each( function() {
+		this.label.contents().not( this.element[ 0 ] ).each( function() {
 
 			// The label contents could be text, html, or a mix. We concat each element to get a
 			// string representation of the label, without the input as part of it.
@@ -252,7 +252,15 @@ $.widget( "ui.checkboxradio", [ $.ui.formResetMixin, {
 	_updateLabel: function() {
 
 		// Remove the contents of the label ( minus the icon, icon space, and input )
-		this.label.contents().not( this.element.add( this.icon ).add( this.iconSpace ) ).remove();
+		var contents = this.label.contents().not( this.element[ 0 ] );
+		if ( this.icon ) {
+			contents = contents.not( this.icon[ 0 ] );
+		}
+		if ( this.iconSpace ) {
+			contents = contents.not( this.iconSpace[ 0 ] );
+		}
+		contents.remove();
+
 		this.label.append( this.options.label );
 	},