Fix rpl.rpl_semi_sync_cond_var_per_thd

rpl.rpl_semi_sync_cond_var_per_thd could sporadically fail with
ER_NET_READ_ERROR, which was not suppressed in the test.

This patch adds the test suppression for that error.

mysql-test/suite/rpl/r/rpl_semi_sync_cond_var_per_thd.result

@@ -2,6 +2,7 @@ include/master-slave.inc
 [connection master]
 connection master;
 call mtr.add_suppression("Got an error reading communication packets");
+call mtr.add_suppression("Could not read packet:.* vio_errno: 1158");
 set @save_bgc_count= @@global.binlog_commit_wait_count;
 set @save_bgc_usec= @@global.binlog_commit_wait_usec;
 set @save_debug_dbug= @@global.debug_dbug;

mysql-test/suite/rpl/t/rpl_semi_sync_cond_var_per_thd.test

@@ -26,6 +26,7 @@
 
 --connection master
 call mtr.add_suppression("Got an error reading communication packets");
+call mtr.add_suppression("Could not read packet:.* vio_errno: 1158");
 set @save_bgc_count= @@global.binlog_commit_wait_count;
 set @save_bgc_usec= @@global.binlog_commit_wait_usec;
 set @save_debug_dbug= @@global.debug_dbug;