Explicitely disable ssl on mariadb service

So the ssl key configuration are not generated in the configuration. As, for
newest version, this creates startup services issues if those are still
present while disabled.

Refs. swh/infra/sysadm-environment#4777

site-modules/profile/manifests/phabricator.pp

@@ -146,6 +146,11 @@ class profile::phabricator {
         innodb_flush_method     => $db_innodb_flush_method,
         innodb_log_file_size    => $db_innodb_log_file_size,
         max_connections         => $db_max_connections,
+        ssl_disable             => true,  # disabled by default but without
+                                          # this, it still generates config
+                                          # keys which prevent new mariadb
+                                          # version from starting. In effect,
+                                          # failing mariadb systemd service
         local_infile            => 0,
       }
     }