Buildsystem/MSVC: Warning fixes

C4800 'type' : forcing value to bool 'true' or 'false' (performance warning)
C4127 conditional expression is constant

src/server/collision/Maps/MapTree.cpp

@@ -295,7 +295,7 @@ namespace VMAP
             success = readChunk(rf, chunk, "GOBJ", 4);
         }
 
-        iIsTiled = bool(tiled);
+        iIsTiled = tiled != '\0';
 
         // global model spawns
         // only non-tiled maps have them, and if so exactly one (so far at least...)