Reset TOI meta after releasing total order in provider

This is to keep the TOI meta available in case the provider
implementation needs it.

include/wsrep/provider.hpp

@@ -366,6 +366,7 @@ namespace wsrep
          * Leave total order isolation critical section
          */
         virtual enum status leave_toi(wsrep::client_id,
+                                      const wsrep::ws_meta& ws_meta,
                                       const wsrep::mutable_buffer& err) = 0;
 
         /**