Merge #758: genwallet p2sh -> p2wpkh

0cd8a73a26 genwallet p2sh -> p2wpkh (nixbitcoin)

Pull request description:

  This PR updates `scripts/genwallet.py` to generate native segwit/bech32 wallets in line with JoinMarket release v0.8.0.

ACKs for top commit:
  kristapsk:
    ACK 0cd8a73a26

Tree-SHA512: 00d4e843bbf12d93855f7741c1321b929278e28545fd02cce51dd6587b7f400fbaeae423f2568e23012271338ba4e1f1f0d8fab6b8fa93eedd5c6e90e48767e8

scripts/genwallet.py

@@ -3,7 +3,7 @@
 import sys
 import os
 from optparse import OptionParser
-from jmclient import load_program_config, add_base_options, SegwitLegacyWallet, create_wallet, jm_single
+from jmclient import load_program_config, add_base_options, SegwitWallet, SegwitLegacyWallet, create_wallet, jm_single
 from jmbase.support import get_log, jmprint
 
 log = get_log()
@@ -23,7 +23,11 @@ def main():
     load_program_config(config_path=options.datadir)
     wallet_root_path = os.path.join(jm_single().datadir, "wallets")
     wallet_name = os.path.join(wallet_root_path, args[0])
-    wallet = create_wallet(wallet_name, password, 4, SegwitLegacyWallet)
+    if jm_single().config.get("POLICY", "native") == "true":
+        walletclass = SegwitWallet
+    else:
+        walletclass = SegwitLegacyWallet
+    wallet = create_wallet(wallet_name, password, 4, walletclass)
     jmprint("recovery_seed:{}"
          .format(wallet.get_mnemonic_words()[0]), "important")
     wallet.close()