Slight optimization with regards to units that are processed.
Added radio image to HUD display when radio is being used in some manner.

Issue: https://github.com/michail-nikolaev/task-force-arma-3-radio/issues/391
Merge pull request #396 from CorruptedHeart/HUDImage

Added radio image to HUD display when radio is being used in some manner...
Reverted change to error message.
Merge pull request #395 from CorruptedHeart/Optimise

Slight optimization with regards to units that are processed.