Core/Maps: Fix crash in ExistMap, fixes issue 4115

--HG--
branch : trunk

src/server/game/Maps/Map.cpp

@@ -78,9 +78,9 @@ bool Map::ExistMap(uint32 mapid,int gx,int gy)
             else
                 ret = true;
         }
+       fclose(pf);
     }
     delete [] tmp;
-    fclose(pf);                                         //close file before return
     return ret;
 }