added missing mapflag

npc: conf/mapflag/noreturn.txt

git-svn-id: https://svn.code.sf.net/p/rathena/svn/branches/stable@913 54d463be-8e91-2dee-dedb-b68131a5f0ec

npc/npcs_athena.conf

@@ -16,6 +16,7 @@ npc: conf/mapflag/nopenalty.txt
 npc: conf/mapflag/nopvp.txt
 npc: conf/mapflag/nosave.txt
 npc: conf/mapflag/noteleport.txt
+npc: conf/mapflag/noreturn.txt
 npc: conf/mapflag/nowarp.txt
 npc: conf/mapflag/nowarpto.txt
 npc: conf/mapflag/pvp.txt