Fixed multiple casts of NPC_REBIRTH interfering with activation of mob death events.

git-svn-id: https://svn.code.sf.net/p/rathena/svn/trunk@13287 54d463be-8e91-2dee-dedb-b68131a5f0ec

src/map/skill.c

@@ -4610,6 +4610,8 @@ int skill_castend_nodamage_id (struct block_list *src, struct block_list *bl, in
 		break;
 
 	case NPC_REBIRTH:
+		if( md && md->state.rebirth )
+			break; // only works once
 		sc_start(bl,type,100,skilllv,-1);
 		break;