Added contrib of L4D server

functions/fn_header

@@ -11,6 +11,8 @@ echo "Linux Game Server Manager"
 echo "by Daniel Gibbs"
 if [ "${gamename}" == "ARMA 3" ]; then
 	echo "contributions by Scarsz"
+elif [ "${gamename}" == "Left 4 Dead" ]; then
+	echo "contributions by Summit Singh Thakur"
 fi
 echo "http://danielgibbs.co.uk"
 echo "================================="