Continuous gtidSet vs loop replication

[c0494133d4]

A	B
exec tx
	exec tx
	and write gtid_executed
found tx.osid=A
skip the executed tx

• We need to update meta gtid, to make gtid continuous
• We should not write gtid_executed for a skipped tx, or it will loop forever

[ghost]

When restarting dtle, the job continues from meta gtid (consul), which is continuous. Then dtle.gtid_executed table will be read and the gtidSet is merged into meta gtid, which might cause temporary intermissions in meta gtid.

[ghost]

Should have been fixed since 7bdc965a.