Revert OCSP stapling to roles mail::mx and lists
Apparently this is buggy with jessie's version of GnuTLS and makes exim4
send the status TLS extension even when not requested, breaking most
clients in the process. Newer versions of exim4 (4.87+) even blacklist
those buggy GnuTLS versions and refuse to enable OCSP.
Exim bug #1664 has the gory details and links to upstream commit fixes:
This reverts commits: