Remove repository url from pypi secret
The dependent change uses the twine default repository url if
none is provided.  This change therefore uses the default.
It also removes the unecessary repository name (as pypi is the
default as well).
Depends-On:
- secret:
name: pypi_secret
data:
- repository: pypi
- repository_url: https://pypi.python.org/pypi/
username: openstackci
password: !encrypted/pkcs1-oaep
- eFMvy6TEF4ImAWbSsG9L/IR9qAZJ3wkqQVbTJ4+ybrprSzvHdoeFLiu5Fr8cpT23AoFPe
