Change default cipher for server configurations to AES-GCM
    
    At the same time, utilize the Negotiable Crypto Parameters (NCP) feature
    in OpenVPN v2.4, which allows clients using the old BF-CBC default cipher
    to connect without any issues.
    
    F-27 Change request: https://fedoraproject.org/wiki/Changes/New_default_cipher_in_OpenVPN
    
    This change was approved in the FESCO meeting 2017-08-04.
    
    Also fix a truncated changelog entry for openvpn-2.4.3-1