Improve CA help notes

Author: timvaillancourt

mongodb_consistent_backup/Common/Config.py

@@ -68,7 +68,7 @@ def makeParser(self):
         parser.add_argument("-a", "--authdb", dest="authdb", help="MongoDB Auth Database (for optional auth - default: admin)", default='admin', type=str)
         parser.add_argument("--ssl.enabled", dest="ssl.enabled", help="Use SSL secured database connections to MongoDB hosts (default: false)", default=False, action="store_true")
         parser.add_argument("--ssl.insecure", dest="ssl.insecure", help="Do not validate the SSL certificate and hostname of the server (default: false)", default=False, action="store_true")
-        parser.add_argument("--ssl.ca_file", dest="ssl.ca_file", help="Path to SSL Certificate Authority file in PEM format", default=None, type=str)
+        parser.add_argument("--ssl.ca_file", dest="ssl.ca_file", help="Path to SSL Certificate Authority file in PEM format (default: use OS default CA)", default=None, type=str)
         parser.add_argument("--ssl.crl_file", dest="ssl.crl_file", help="Path to SSL Certificate Revocation List file in PEM or DER format (for optional cert revocation)", default=None, type=str)
         parser.add_argument("--ssl.client_cert_file", dest="ssl.client_cert_file", help="Path to Client SSL Certificate file in PEM format (for optional client ssl auth)", default=None, type=str)
         parser.add_argument("-L", "--log-dir", dest="log_dir", help="Path to write log files to (default: disabled)", default='', type=str)