ipa: make sure view name is initialized at startup
    
    sysdb_master_domain_update() can only set the view name properly if it was not
    set before but it might be called multiple times before the view name is
    available if the cache is empty. Since ipa_apply_view() keeps track if
    the view name was already set at startup or not the name can safely be
    cleaned here before sysdb_master_domain_update() is called.
    
    Resolves:
    https://pagure.io/SSSD/sssd/issue/3501
    
    Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>
    (cherry picked from commit f00591a4615720640cf01b1c408315b57dd397dc)