[BUGFIX] explicitly check if the colPos value is inside an array

[lukasniestroj]

I encountered this issue with typo3/cms-core:10.4 and gridelements:^10.

Scenario: I have a backendlayout with restrictions on colPos "0" in my backendlayout. (allowed { CType = text,html } } ) In addition i have a simple gridelement with another restriction (allowed { CType = image } } ) Gridelements passes "-1" as colPos value but this value is parsed as "0" -> this results in wrong restrictions. The dropdown has text, html (wrong) and not image (expected)

[tlueder]

I'm having the same problem.

Setup: Typo3 v11.5.4 in Debug mode php 8.0