ipatests: update the expected sha256sum of epn.conf file
The file epn.conf has been updated when fixing issue 9145
and the test test_epn.py::TestEPN::test_EPN_config_file
is comparing its sha256sum with the checksum of the
shipped file from the package ipa-client-epn.
The expected checksum needs to be updated.
Fixes: https://pagure.io/freeipa/issue/9146
Reviewed-By: Rob Crittenden <rcritten@redhat.com>