Prior to this change, if the following conditions were true:
1) A Koji client uses SSL authentication,
2) The user does not set the "serverca" option for their profile,
3) The user does not have a "~/.koji/serverca.crt" file present,
Then Koji did not use the default CA store to validate the hub's CA.
read_defaults() was setting the "serverca" value to an empty string ""
in these cases. This led to an AuthError in ssl_login() for the empty
string:
raise AuthError("Server CA %s doesn't exist or is not accessible" % serverca)
Update ssl_login() to ignore empty strings in this case, treating them
the same as None.
The code in _sendOneCall() already checks this value in a similar way,
with "if verify:", so we're matching that behavior here.
With this change, Koji clients will fall back to using the default CA
store.
19dabc0eda