Fix sponge PEX/PM migration issue with defaults

sponge/src/main/java/me/lucko/luckperms/sponge/migration/MigrationPermissionManager.java

@@ -127,6 +127,9 @@ public class MigrationPermissionManager extends SubCommand<Object> {
             // Make a LuckPerms user for the one being migrated
             plugin.getStorage().loadUser(uuid, "null").join();
             User user = plugin.getUserManager().get(uuid);
+            if (user.getNodes().size() <= 1) {
+                user.clearNodes(false);
+            }
             migrateSubject(pmUser, user);
             plugin.getStorage().saveUser(user);
             plugin.getUserManager().cleanup(user);

sponge/src/main/java/me/lucko/luckperms/sponge/migration/MigrationPermissionsEx.java

@@ -153,6 +153,9 @@ public class MigrationPermissionsEx extends SubCommand<Object> {
             // Make a LuckPerms user for the one being migrated
             plugin.getStorage().loadUser(uuid, "null").join();
             User user = plugin.getUserManager().get(uuid);
+            if (user.getNodes().size() <= 1) {
+                user.clearNodes(false);
+            }
             migrateSubject(pexUser, user);
             plugin.getStorage().saveUser(user);
             plugin.getUserManager().cleanup(user);