Followup r15245, fixed gcc warning

git-svn-id: https://svn.code.sf.net/p/rathena/svn/trunk@15247 54d463be-8e91-2dee-dedb-b68131a5f0ec

src/map/log.h

@@ -6,6 +6,7 @@
 
 //#include "map.h"
 struct map_session_data;
+struct block_list;
 struct mob_data;
 struct item;