Fix regression introduced by #638

[olivierHa]

Hello

Fixing #638 has introduced a regression with commit ad3862d
Indeed, user isn't defined.

Regards

[coveralls]

Coverage remained the same at 24.667% when pulling c4ea8f8 on olivierHa:bugfix/user_not_defined into f2bece4 on python-diamond:master.

[JakSla]

this can also be used as an alternative
user = config['server']['user']

[shortdudey123]

Can you rebase on master? As a side note, the alternative mentioned above won't work since user has two config sources, not one.