Do not track evolution-data-server under CVE-2018-15587

This was added back in f6f251cf but the
CVe is specific to the OpenPGP signatures beeing spoofed.

Apparently Ubuntu does track the second issue, for email that is not
encyrpted to look as encrypted, and fixed in evolution-data-server still
under this CVE while other (correctly?) do not.

Cf.
https://people.canonical.com/~ubuntu-security/cve/2018/CVE-2018-15587.html
and other still as well relate to evolution-data-server, cf
https://bugzilla.redhat.com/show_bug.cgi?id=1677650#c2 .