Followings are the settings I use for my server

<VirtualHost *:80>
        ServerName gitlab.its-newid.net

        ProxyRequests   Off
        ProxyVia        Off
        ProxyPreserveHost       On

        <Proxy *>
                Require all granted
        </Proxy>

        ProxyPass / https://192.168.10.8/ nocanon
        ProxyPassReverse / https://192.168.10.8/ nocanon
        AllowEncodedSlashes NoDecode
        RequestHeader set X-Forwarded-Proto "https"
</VirtualHost>

<VirtualHost *:443>
        ServerName gitlab.its-newid.net

        ProxyRequests   Off
        SSLProxyEngine on
        ProxyVia        Off
        ProxyPreserveHost       On

        <Proxy *>
                Require all granted
        </Proxy>

        ProxyPass / https://192.168.10.8/ nocanon
        ProxyPassReverse / https://192.168.10.8/ nocanon
        AllowEncodedSlashes NoDecode
        RequestHeader set X-Forwarded-Proto "https"

        SSLEngine on
        SSLProtocol all -SSLv2 -SSLv3
        SSLCipherSuite HIGH:MEDIUM:!SSLv2:!PSK:!SRP:!ADH:!AECDH
        SSLCertificateKeyFile "cert.key"
        SSLCertificateFile "crt.pem"
        SSLCACertificateFile "cert.ca-bundle"
</VirtualHost>