bitcoind: Use loadwallet when restarting

When restarting a docker-compose set of containers we might already
have created the wallet, so load it instead.

code/docker/bitcoind/bitcoind-entrypoint.sh

@@ -15,8 +15,10 @@ echo "Importing demo private key"
 echo "Bitcoin address: " ${address}
 echo "Private key: " ${privkey}
 echo "================================================"
-bitcoin-cli -datadir=/bitcoind createwallet regtest
-bitcoin-cli -datadir=/bitcoind importprivkey $privkey
+# If restarting the wallet already exists, so don't fail if it does,
+# just load the existing wallet:
+bitcoin-cli -datadir=/bitcoind createwallet regtest || bitcoin-cli -datadir=/bitcoind loadwallet regtest
+bitcoin-cli -datadir=/bitcoind importprivkey $privkey || true
 
 # Executing CMD
 echo "$@"