Update remoteexec.txt

!="spawn BIS_Effects_AirDestructionStage2" !="]spawn BIS_Effects_AirDestructionStage2"

replaced with

!"spawn BIS_Effects_AirDestructionStage2"

the old version still kicked on helicrash.
Merge pull request #865 from infiSTAR/patch-1

Update remoteexec.txt