MariaDB: wp db repair --verbose test fails because mariadb-check only prints "Connecting" at higher verbosity #335

Split off from #309 / #334.

Once the --ssl-verify-server-cert warnings are silenced (#334), the MariaDB
Behat run surfaces one remaining pre-existing failure in
features/db.feature:155 ("DB Operations with passed-in options"):

When I try `wp db repair --verbose`
Then STDERR should contain:
  """
  Connecting
  """

wp db repair --verbose runs mariadb-check --verbose. MySQL's mysqlcheck
prints # Connecting to ... to STDERR at a single --verbose, but MariaDB's
mariadb-check only prints it at verbosity level 2:

$ mariadb-check --verbose ...   # no "Connecting" line
$ mariadb-check -v -v ...        # "# Connecting to localhost..."

So the assertion passes on MySQL and fails on MariaDB.

Options

• Relax the assertion to a string both clients emit at --verbose.
• Assert the connection line only where it is expected (branch/skip on MariaDB).

Not blocking #334, which fixes the SSL warnings.