NetClient pointer mismatch crash fix
NetClient pointer mismatch crash fix

Check if fOnReceiveData is assigned (TKMServerQuery could disconnect client but some messages can still arrive and we are in a different thread at this moment)

Alexandr57/kam_remake,thibmo/kam_remake,thibmo/kam_remake,Alexandr57/kam_remake,reyandme/kam_remake,reyandme/kam_remake,reyandme/kam_remake,Alexandr57/kam_remake,Alexandr57/kam_remake,reyandme/kam_remake,Alexandr57/kam_remake,thibmo/kam_remake,Alexandr57/kam_remake,thibmo/kam_remake,thibmo/kam_remake,reyandme/kam_remake