Fixed issue found by buildbot

mysql-test/suite/innodb/t/innodb_bug51920.test:
  Add another possible connect error

mysql-test/suite/innodb/t/innodb_bug51920.test

@@ -36,7 +36,7 @@ let $wait_condition =
 # depending on platform.
 #
 connection con1;
--- error 1317, 2006, 2013
+-- error 1317, 2006, 2013, 1927
 reap;
 connection default;
 DROP TABLE bug51920;