Remove caJarSigningCert profile and related code
    
    The caJarSigningCert profile was used for issuing the object signing
    certificate for signing the Firefox auto-configuration extension
    (XPI).  We removed the extension and object signing certificate some
    time ago, so remove the profile and the related code that sets it
    up.
    
    Fixes: https://pagure.io/freeipa/issue/7226
    Reviewed-By: Rob Crittenden <rcritten@redhat.com>