MDEV-11530: wsrep_info.plugin fails sporadically in buildbot

Add the warning to the global_suppressions list.

plugin/wsrep_info/mysql-test/wsrep_info/suite.pm

@@ -33,6 +33,7 @@ push @::global_suppressions,
      qr(WSREP: last inactive check more than .* skipping check),
      qr(WSREP: Gap in state sequence. Need state transfer.),
      qr(WSREP: Failed to prepare for incremental state transfer: .*),
+     qr(WSREP: SYNC message from member .* in non-primary configuration. Ignored.),
    );