Truly decouple wallet from chainparams for -fallbackfee (Jorge Timón)
Pull request description:
Before it was 0 by default for main and 20000 for test and regtest.
Now it is 0 by default for all chains, thus there's no need to call Params().
Also now the default for main is properly documented.
Suggestion for release notes:
-fallbackfee was 0 (disabled) by default for the main chain, but 20000 by default for the test chains. Now it is 0 by default for all chains. Testnet and regtest users will have to add fallbackfee=20000 to their configuration if they weren't setting it and they want it to keep working like before.
Should I propose them to the wiki for the release notes or only after merge?
For more context, see https://github.com/bitcoin/bitcoin/pull/16402#issuecomment-515701042
https://github.com/bitcoin/bitcoin/pull/16524/commits/ea4cc3a7b36a9c77dbf0aff439da3ef0ea58e6e4
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Depends on D7061
Backport of Core PR16524