Conditional statements for OpenID Connect provider selection should be improved

[gbarbon]

Is your feature request related to a problem? Please describe.
The conditional expressions in the run-console script for triggering the right OpenID Connect provider should be integrated with an else statement, otherwise the presence of old 'dirty' environment variables of multiple providers might cause unexpected behaviours.

Describe the solution you'd like
Use of elif for the provider selection. The last case should be the generic one, that will also act as a sort of 'fallback' in case of 'dirty' environment. In case the combination of environment variable is not compatible with any provider, no provider will be triggered.

Describe alternatives you've considered
n/a

Additional context
It is worth noting that the proposed solution would not solve completely the issue, but only mitigate it.