fix for issue #1405

This fixes the issue with this error:
"VERSION CHECK: Anim:1.0.5 Epoch:1.0.4.2 EpochB:1.0.5 Sfx:1.0.5
DayZ:1.0.5"
Fresnel k must be >0, given n=0.8,k=0
Fresnel k must be >0, given n=0.8,k=0
"End Mission"