[BUG] checks: fix support of Mysqld >= 5.5 for mysql-check

mysqld >= 5.5 want the client to announce 4.1+ authentication support, even if we have no password, so we do this.
I also check on a debian potato mysqld 3.22 and it works too so i assume we are good from 3.22 to 5.5.

[WT: this must be backported to 1.4]
2 files changed