ipatests: test ipa_server_certinstall with an IPA-issued cert
    
    ipa-server-certinstall takes a slightly different code path if
    the replacement certificate is IPA-issued so exercise that path.
    
    This replaces the Apache cert with itself which is a bit of a no-op
    but it still goes through the motions.
    
    https://pagure.io/freeipa/issue/8204
    
    Signed-off-by: Rob Crittenden <rcritten@redhat.com>
    Reviewed-By: Fraser Tweedale <ftweedal@redhat.com>