Multiselect doesn't disable options if selectionLimit reached by default value

[FrEaKmAn]

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Plunkr Case (Bug Reports)
Please demonstrate your case at stackblitz by using the issue template below. Issues without a test case have much less possibility to be reviewd in detail and assisted.

https://stackblitz.com/edit/ngprime-multiselect-qvvtfu?file=src/app/app.component.ts

Current behavior

I have 2 values already passed as default value with selectionLimit to 2. Once I open dropdown, other options are still enabled. Once I click on one of them, it closes the dropdown, disables options and doesn't select any value.

Expected behavior

I would expect that when I open dropdown, options should already be disabled.

Minimal reproduction of the problem with instructions

Follow stackblitz test link and open dropdown. You will see other options as selectable.

• Angular version: 7.X

• PrimeNG version: 7.X

• Browser: all

• Language: all

• Node (for AoT issues): node --version =