Add backup link in case the devpi local server not updated.

[amrsoll]

my devpi config wasn't quite up to snuff... oh well, at least pip will search on pypi too :)

N.B devpi makes this endeavour much more bearable pffuui ^^

[guysoft]

This should be added as a config variable, same as the first index. So people could change it and see from the config file where the packages they are using are arriving from.

[guysoft]

Hey, a thought about this - why not add the value form BASE_PYPI_INDEX that already exists there?

[guysoft]

Closing if no reply