ipatests: fix healthcheck test for --indent option
    
    ipa-healthcheck --indent option expects an integer. The error
    message changed with ipa-healthcheck 0.13.
    Recent versions also check that the value is in the range 0-32.
    
    The test must be compatible with old and new versions.
    
    Signed-off-by: Florence Blanc-Renaud <flo@redhat.com>
    Reviewed-By: Rob Crittenden <rcritten@redhat.com>