Remove dead client CA code

The client CA is only needed to for authentication on the server side,
not for authentication on the client side. Therefore remove it from all
client login code.

vm/kojivmd

@@ -130,7 +130,7 @@ def get_options():
                 'offline_retry_interval': 120,
                 'allowed_scms': '',
                 'cert': '/etc/kojivmd/client.crt',
-                'ca': '/etc/kojivmd/clientca.crt',
+                'ca': '',  # FIXME: Remove in next major release
                 'serverca': '/etc/kojivmd/serverca.crt'}
     if config.has_section('kojivmd'):
         for name, value in config.items('kojivmd'):
@@ -1066,7 +1066,7 @@ if __name__ == "__main__":
     if os.path.isfile(options.cert):
         try:
             # authenticate using SSL client certificates
-            session.ssl_login(options.cert, options.ca,
+            session.ssl_login(options.cert, None,
                               options.serverca)
         except koji.AuthError, e:
             quit("Error: Unable to log in: %s" % e)

vm/kojivmd.conf

@@ -50,8 +50,5 @@ from_addr=Koji Build System <buildsys@example.com>
 ;client certificate
 ;cert = /etc/kojivmd/client.crt
 
-;certificate of the CA that issued the client certificate
-;ca = /etc/kojivmd/clientca.crt
-
 ;certificate of the CA that issued the HTTP server certificate
 ;serverca = /etc/kojivmd/serverca.crt