mod_nss: stop using NSSProtocols TLS 1.0 and 1.1
    
    TLS 1.0 and 1.1 will be deprecated in march 2020, and TLS 1.2 should be used
    instead.
    - During installation of IPA server, the NSS module used by apache server
    is configured with TLS 1.2 only.
    - During upgrade, the NSS module is configured with TLS 1.2 only (other
    protocols are removed).
    
    Fixes: https://pagure.io/freeipa/issue/7995
    Reviewed-By: Christian Heimes <cheimes@redhat.com>
    Reviewed-By: Rob Crittenden <rcritten@redhat.com>