BUG #13933. Ensure ColorArrayName doesn't raise exceptions.

Ensure that older scripts that simply set arraynames for ColorArrayName property
don't raise exceptions in symmetric-mpi mode i.e. coprocessing mode.

Change-Id: I4b15275ac54ced7b5facb969f20f83fb300b346f
Merge topic '13933_fix_python_missing_arrays' into next

617617f BUG #13933. Ensure ColorArrayName doesn't raise exceptions.