change pki-core required version for replica promotion

Required PKI changes, namely:
  https://fedorahosted.org/pki/ticket/1414
  https://fedorahosted.org/pki/ticket/1580

Are included in pki-core 10.2.6-5 reps. 10.2.6-10

10.2.7 does not exist yet.

Reviewed-By: Martin Babinsky <mbabinsk@redhat.com>

freeipa.spec.in

@@ -141,8 +141,8 @@ Requires(post): systemd-units
 Requires: selinux-policy >= %{selinux_policy_version}
 Requires(post): selinux-policy-base >= %{selinux_policy_version}
 Requires: slapi-nis >= 0.54.2-1
-Requires: pki-ca >= 10.2.7
-Requires: pki-kra >= 10.2.7
+Requires: pki-ca >= 10.2.6-10
+Requires: pki-kra >= 10.2.6-10
 Requires(preun): python systemd-units
 Requires(postun): python systemd-units
 Requires: python-dns >= 1.11.1