Arma3: improve exit handling for headless clients (#476)

arma3runhc.sh

@@ -38,13 +38,14 @@ for i in $(seq 1 "$1"); do
 done
 
 # Monitor server process and terminate headless clients
-# when server terminates
-trap 'kill "${clients[@]}" >/dev/null 2>&1' SIGTERM
+# when server terminates or SIGTERM/SIGINT received
+trap 'for client in "${clients[@]}"; do kill "$client" >/dev/null 2>&1; done; wait' SIGTERM SIGINT
 while true; do
   if ! $netcommand -uln | grep -q ":$3 "; then
     for client in "${clients[@]}"; do
       kill "$client" >/dev/null 2>&1
     done
+    wait
     exit 0
   fi
   sleep 1