update .gitignore
update .gitignore

during build on 10.2 following files are generated:

  * scripts/galera_new_cluster
  * scripts/galera_recovery
  * support-files/mariadb.service
  * support-files/mariadb.pp

and they are untracked for git. Let's add them to .gitignore

natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2