Use .prop() instead of .attr()/.removeAttr() to set boolean attributes

Change-Id: I4988316b202c19f851f2c05e3d07acc8c5ea38cf

resources/js/ext.uls.displaysettings.js

@@ -511,7 +511,7 @@
 		 */
 		markDirty: function () {
 			this.dirty = true;
-			this.$parent.$window.find( 'button.uls-settings-apply' ).removeAttr( 'disabled' );
+			this.$parent.$window.find( 'button.uls-settings-apply' ).prop( 'disabled', false );
 		},
 
 		/**

resources/js/ext.uls.inputsettings.js

@@ -175,9 +175,9 @@
 			$inputMethodItem = $( '<input type="radio">' ).attr( {
 				name: 'ime',
 				id: imeId,
-				value: imeId,
-				checked: selected
-			} );
+				value: imeId
+			} )
+			.prop( 'checked', selected );
 
 			$imeLabel.append( $inputMethodItem );