when replay optimizations are disabled we still create database sessi…

…ons however, we were never committing those database sessions leaving lots of stale undo states around until the very end of the replay

libraries/chain/controller.cpp

@@ -1846,6 +1846,11 @@ struct controller_impl {
             // On replay, log_irreversible is not called and so no irreversible_block signal is emittted.
             // So emit it explicitly here.
             emit( self.irreversible_block, bsp );
+
+            if (!self.skip_db_sessions(s)) {
+               db.commit(bsp->block_num);
+            }
+
          } else {
             EOS_ASSERT( read_mode != db_read_mode::IRREVERSIBLE, block_validate_exception,
                         "invariant failure: cannot replay reversible blocks while in irreversible mode" );