Use of ["addresses"] will be deprecated in Bitcoin Core v22

[Sjors]

bitcoin/bitcoin#20286

• The following RPCs: gettxout, getrawtransaction, decoderawtransaction,
  decodescript, gettransaction, and REST endpoints: /rest/tx,
  /rest/getutxos, /rest/block deprecated the following fields (which are no
  longer returned in the responses by default): addresses, reqSigs.
  The -deprecatedrpc=addresses flag must be passed for these fields to be
  included in the RPC response. This flag/option will be available until v23, at which
  point the deprecation will be removed entirely. Note that these fields are attributes of
  the scriptPubKey object returned in the RPC response. However, in the response
  of decodescript these fields are top-level attributes, and included again as attributes
  of the scriptPubKey object. (#20286)

Replacing ['scriptPubKey']['addresses'][0] in wallet_send_sign_psbt.jinja with ['scriptPubKey']['address'] seems to do the trick.

[ben-kaufman]

Thanks for the heads up, I've made this PR to check for this field when the addresses isn't found #1180