class and table schema now conform to JSON

src/engine/devcmd/cmds/PurgeObjectsCmd.java

@@ -42,7 +42,7 @@ public class PurgeObjectsCmd extends AbstractDevCmd {
 
     private static void PurgeWalls(Zone zone, PlayerCharacter pc) {
 
-        if (!zone.isPlayerCity)
+        if (!zone.isGuildZone)
             return;
 
         for (Building building : zone.zoneBuildingSet) {