HBASE-23694 After RegionProcedureStore completes migration of WALProcedureStore, still running WALProcedureStore.syncThread keeps trying to delete now inexistent log files. (#1048)

Signed-off-by: Duo Zhang <zhangduo@apache.org>

hbase-server/src/main/java/org/apache/hadoop/hbase/procedure2/store/region/RegionProcedureStore.java

@@ -364,6 +364,7 @@ public class RegionProcedureStore extends ProcedureStoreBase {
       throw new IOException("Failed to delete the WALProcedureStore migrated proc wal directory " +
         procWALDir);
     }
+    store.stop(true);
     LOG.info("Migration of WALProcedureStore finished");
   }