simplify mysql slurm user creation

[martbhell]

https://github.com/CSC-IT-Center-for-Science/ansible-role-slurm/blob/master/tasks/dbd.yml#L74

has

 - name: check if slurm db user exists
    mysql_user: "name=slurm state=present"
    register: mysqlslurmuser
    ignore_errors: yes
    tags: debug

And then later we:

  - name: create slurm db user if it does not exist
    mysql_user: "name=slurm password={{ slurm_mysql_password }} priv=slurm_acct_db.*:ALL state=present update_password=always"
    when: mysqlslurmuser|failed or mysqlslurmuser|changed

Could we remove the first one (which creates the sql user) and run the mysql_user module/task just once?