selectmenu content differs when created or refreshed when overriding _renderItem

[gibe]

When creating a selectmenu, the content of the button is the text of the selected option in the original menu.

When refreshing a selectememu, the content of the button is the text of the selected <li> in the menu widget.

By default both of the same, but when overriding _renderItem their content may differ.

The lines setting the text are:

• for creation (l108): this._setText( this.buttonText, this.element.find( "option:selected" ).text() );
• for refresh (l194): this._setText( this.buttonText, this._getSelectedItem().text() );

I guess that both values make sense. However only one should be set.

[Scott González]

This code no longer exists in master. See #10142.

Fixed by fb4124b7af4e87712eca9893f7aefb5fee7905de.