Proxies require lowercase

[Sp5rky]

Describe the bug
When typing the proxy_providers in capitals for the 2 letter countries it fails

To Reproduce
In devine.yaml adding the proxies causes --proxy basic:JP or basic:jp to not be recognized and fails to connect

proxy_providers:
  basic:
    JP:
      - https://<user>:<password>@<host>:<port>
    SG: 
      - https://<user>:<password>@<host>:<port>
    PH:
      - https://<user>:<password>@<host>:<port>

Expected behavior
Connect to proxy regardless of capitals

Screenshots

Additional context
changing the devine.yaml to lowercase like the --proxy basic:jp now works correctly

proxy_providers:
  basic:
    jp:
      - https://<user>:<password>@<host>:<port>
    sg: 
      - https://<user>:<password>@<host>:<port>
    ph:
      - https://<user>:<password>@<host>:<port>