Added a nil check for resp.GetError() in the EOS gRPC client. This fixes a nil pointer dereference in the RollbackToVersion method (#4896)

Co-authored-by: Jesse Geens <[email protected]>

Author: jessegeens

changelog/unreleased/restorefileversion-nilptr.md

@@ -0,0 +1,3 @@
+Bugfix: fix nilpointer error in RollbackToVersion
+
+https://github.com/cs3org/reva/pull/4896

pkg/eosclient/eosgrpc/eosgrpc.go

@@ -1544,8 +1544,9 @@ func (c *Client) RollbackToVersion(ctx context.Context, auth eosclient.Authoriza
 		return errtypes.InternalError(fmt.Sprintf("nil response for uid: '%s' ", auth.Role.UID))
 	}
 
-	log.Info().Str("func", "RollbackToVersion").Int64("errcode", resp.GetError().Code).Str("errmsg", resp.GetError().Msg).Msg("grpc response")
-
+	if resp.GetError() != nil {
+		log.Info().Str("func", "RollbackToVersion").Int64("errcode", resp.GetError().Code).Str("errmsg", resp.GetError().Msg).Msg("grpc response")
+	}
 	return err
 }