ipa-acme-manage: user a cookie created for the communication with dogtag REST endpoints
    
    The cookie in ACME processing was supposed to be passed as a part of the
    REST request but we did not pass those additional headers. Pylint on
    Rawhide noticed that headers objects were left unused.
    
    2020-11-13T11:26:46.1038078Z Please wait ...
    2020-11-13T11:26:46.1038385Z
    2020-11-13T11:28:02.8563776Z ************* Module ipaserver.install.ipa_acme_manage
    2020-11-13T11:28:02.8565974Z ipaserver/install/ipa_acme_manage.py:50: [W0612(unused-variable), acme_state.__exit__] Unused variable 'headers')
    2020-11-13T11:28:02.8567071Z ipaserver/install/ipa_acme_manage.py:57: [W0612(unused-variable), acme_state.enable] Unused variable 'headers')
    2020-11-13T11:28:02.8568031Z ipaserver/install/ipa_acme_manage.py:63: [W0612(unused-variable), acme_state.disable] Unused variable 'headers')
    
    Fixes: https://pagure.io/freeipa/issue/8584
    Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>
    Reviewed-By: Rob Crittenden <rcritten@redhat.com>