Don't install posgres on virtu_adh

hosts

@@ -168,7 +168,8 @@ tealc.adm.crans.org
 gulp.cachan-adm.crans.org
 
 [postgres:children]
-virtu
+virtu_adm
+virtu_cachan
 
 [prefix_delegation]
 routeur-gulp.cachan-adm.crans.org
@@ -247,14 +248,18 @@ zamok-tmtc.adm.crans.org
 irc.adm.crans.org
 zamok.adm.crans.org
 
-[virtu]
+[virtu_adh]
+odlyd.adm.crans.org
+stitch.adm.crans.org
+
+[virtu_adm]
 daniel.adm.crans.org
 jack.adm.crans.org
-odlyd.adm.crans.org
 sam.adm.crans.org
-stitch.adm.crans.org
 
 [virtu:children]
+virtu_adh
+virtu_adm
 virtu_cachan
 
 [virtu_cachan]