tests: ca-less to ca-full - remove certupdate
    
    After commits 8960141 and 97942a7 we do not need to run
    ipa-certupdate command anymore when switching to ca-full.
    
    This patch removes the above mentioned commands in order to
    properly test the scenario.
    
    https://pagure.io/freeipa/issue/7309
    
    Reviewed-By: Fraser Tweedale <ftweedal@redhat.com>