toggeable p-menu displays no label with ui-fluid css class applied

[SirDieter]

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http://plnkr.co/edit/jZBesWbZ459Jq0m3ppYm?p=preview

Current behavior

When you toggle the menu, it displays no label / the label is too far too the left
Expected behavior

The label is correctly positioned in the menu option

Minimal reproduction of the problem with instructions

Please tell us about your environment:

• Angular version: 4.3.6

• PrimeNG version: 4.1.3

• Browser: [all]

• Language: [all]