Fix inbox deletion perm

src/main/java/com/intellectualcrafters/plot/commands/Inbox.java

@@ -136,6 +136,7 @@ public class Inbox extends SubCommand {
                 case "delete": {
                     if (!inbox.canModify(plot, player)) {
                         sendMessage(player, C.NO_PERM_INBOX_MODIFY);
+                        return false;
                     }
                     if (args.length != 3) {
                         sendMessage(player, C.COMMAND_SYNTAX, "/plot inbox " + inbox.toString() + " delete <index>");

src/main/java/com/intellectualcrafters/plot/util/ClusterManager.java

@@ -216,6 +216,10 @@ public class ClusterManager {
     }
 
     public static PlotId estimatePlotId(final Location loc) {
+        Plot plot = MainUtil.getPlot(loc);
+        if (plot != null) {
+            return plot.id;
+        }
         final PlotId a = new PlotId(0, 0);
         final PlotId b = new PlotId(1, 1);
         int xw;