rest: fix sql typo in og_set_client_mode

Replace invalid variable @ipserveradm by @serverip in the SQL query of
og_set_client_mode.

@ipserveradm is a typo as this variable does not exists. This ends up
feeding a string to the legacy setclientmode code and crashes.

This bug also caused problems when adding clients via ogCP or any other
command that required running the set client mode logic.

Fixes: e080fd5526
(rest: add "server=" boot param in set client mode)

src/rest.c

@@ -1108,7 +1108,7 @@ static int og_set_client_mode(struct og_dbi *dbi, const char *mac,
 		"' ogshare=', @serverip, "
 		"' oglivedir=', ordenadores.oglivedir, "
 		"' ogprof=', IF(ordenadores.idordenador=aulas.idordprofesor, 'true', 'false'), "
-		"' server=', @ipserveradm, "
+		"' server=', @serverip, "
 		"IF(perfileshard.descripcion<>'', CONCAT(' hardprofile=', REPLACE(TRIM(perfileshard.descripcion), ' ', '_')), ''), "
 		"IF(aulas.ntp<>'', CONCAT(' ogntp=', aulas.ntp), ''), "
 		"IF(aulas.dns<>'', CONCAT(' ogdns=', aulas.dns), ''), "