generic userid: use the new USERID api

recent changes in trunk allow us to specify the userid inside the openwrt makefile.
the info is stored int he meta data of the IPK contorl file and users are generated
by the new generic postinst trigger.

Signed-off-by: John Crispin <blogic@openwrt.org>

net/openssh/files/sshd.init

@@ -18,8 +18,6 @@ start_service() {
 			}
 		}
 	}; done
-	user_exists sshd 22 || user_add sshd 22 22 sshd /var/empty
-	group_exists sshd 22 || group_add sshd 22 
 	mkdir -m 0700 -p /var/empty
 
 	procd_open_instance