[cashtab + ecash-herald + explorer] revert to previous chronik instance ordering

Summary:
With chronik-native1 indexed, back out the temporary swaps

Open review question -- mb we should have some apps default to 2, others to 1

Test Plan: Confirm chronik-native1 is the first server for all apps, as was the original case.

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Subscribers: Fabien

Differential Revision: https://reviews.bitcoinabc.org/D16585