Merge branch '6231-php-5-4-incompatibility-array_column' into 'develop'

Resolve "php 5.4 incompatibility array_column"

Closes #6231

See merge request ispconfig/ispconfig3!1524
1 job for develop in 13 seconds (queued for 4 seconds)
Status Name Job ID Coverage
  Syntax
passed syntax_diff:lint #13226

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