Add SSL Protocol and Cipher config to default vhost

Let's follow best practice and disable weak ciphers and protocols.

Change-Id: I4f5075f3e23deebd93da2be8a6609c5e195924e5
diff --git a/horizon/files/openstack-dashboard.conf.RedHat b/horizon/files/openstack-dashboard.conf.RedHat
index 2a59194..1742bde 100644
--- a/horizon/files/openstack-dashboard.conf.RedHat
+++ b/horizon/files/openstack-dashboard.conf.RedHat
@@ -76,6 +76,8 @@
   ServerName {{ server.host.name }}
 
   SSLEngine On
+  SSLProtocol +TLSv1 +TLSv1.1 +TLSv1.2
+  SSLCipherSuite HIGH:!RC4:!MD5:!aNULL:!eNULL:!EXP:!LOW:!MEDIUM
   SSLCertificateFile {{ server.certs_dir }}/{{ server.host.name }}.crt
   SSLCertificateKeyFile {{ server.private_dir }}/{{ server.host.name }}.key
   SSLCertificateChainFile {{ server.certs_dir }}/{{ server.ssl.authority }}-chain.crt