[RCU] Help with Apache rewriterule to force roundcube to use https

I am working on Centos7 which provides roundcubemail 1.1.7 and Apache 2.4.

My current server is Redsleeve6 (Centos6 for armv7) which I installed roundcubemail 1.0.4.

With help here 4 years ago I developed a rewrite rule:

<VirtualHost *:80> ServerName webmail.test.htt-consult.com ServerAlias webmail

 RewriteEngine On
     RewriteCond  %{SERVER_PORT} !^443$
     RewriteRule ^.*$ https://%{SERVER_NAME}%{REQUEST_URI} [L,R]
     ExpiresDefault "access plus 10 years"
     AddOutputFilterByType DEFLATE text/html text/plain text/xml
 php_admin_flag session.cookie_secure "1"

</VirtualHost>

This is not working 'right' in Apache 2.4. It seems to redirecting ALL accesses to the server to https, not just to the virtual host of webmail.test.htt-consult.com.

So looking at Harald's post from back in 12/31/2012, I tried:

<VirtualHost *:80> ServerName webmail.test.htt-consult.com ServerAlias webmail

      RewriteEngine On
      ReWriteCond %{HTTP_HOST} =webmail.test.htt-consult.com [NC]
      RewriteCond %{SERVER_PORT} !=443
      RewriteRule ^.*$ https://%{SERVER_NAME}%{REQUEST_URI} [L,R]
      ExpiresDefault "access plus 10 years"
      AddOutputFilterByType DEFLATE text/html text/plain text/xml
      php_admin_flag session.cookie_secure "1"

</VirtualHost>

And that is even worst. Attempts to access z9m9z.test.htt-consult.com/mailadmin just loop. Take this out and I can get to mailadmin.

So can someone help me here with current rewriterules to force roundcube to https while not impacting on other uses of the server?

thanks