will only overwrite on first occurance

lgsm/modules/command_update_linuxgsm.sh

@@ -85,7 +85,7 @@ if [ "${script_diff}" != "" ]; then
 	sed -i "s+gamename=\"core\"+gamename=\"${gamename}\"+g" "${rootdir}/${selfname}"
 	sed -i "s+githubuser=\"GameServerManagers\"+githubuser=\"${githubuser}\"+g" "${rootdir}/${selfname}"
 	sed -i "s+githubrepo=\"LinuxGSM\"+githubrepo=\"${githubrepo}\"+g" "${rootdir}/${selfname}"
-	sed -i "s+githubbranch=\"master\"+githubbranch=\"${githubbranch}\"+g" "${rootdir}/${selfname}"
+	sed -i "s+githubbranch=\"master\"+githubbranch=\"${githubbranch}\"+g;q" "${rootdir}/${selfname}"
 
 	if [ $? != "0" ]; then
 		fn_print_fail_eol_nl