Make account parameter optional in API calls

Account defaults to 0 for getmasterxpub and getdescriptors which is a good, safe choice for most users.

docs/BitcoinCoreKeys.md

@@ -40,7 +40,7 @@ This is an example of `eclair-signer.conf` configuration file:
 
 3) Configure Eclair to handle private keys for this wallet
 
-Set `eclair.bitcoind.wallet` to the name of the wallet just created (`eclair` in the example above) and restart Eclair.
+Set `eclair.bitcoind.wallet` to the name of the wallet in your `eclair-signer.conf` file (`eclair` in the example above) and restart Eclair.
 Eclair will automatically create a new, empty, descriptor-enabled, watch-only wallet in Bitcoin Core and import its descriptors.
 
 :warning: Eclair will not import descriptors if the timestamp set in your `eclair-signer.conf` is more than 2 hours old. If the mnmeonics and
@@ -50,7 +50,7 @@ the steps described in the next section.
 You now have a Bitcoin Core watch-only wallet for which only your Eclair node can sign transactions. This Bitcoin Core wallet can
 safely be copied to another Bitcoin Core node to monitor your onchain funds.
 
-You can also use `eclair-cli getmasterxpub --account=0` to get a BIP32 extended public key that you can import into any compatible Bitcoin wallet
+You can also use `eclair-cli getmasterxpub` to get a BIP32 extended public key that you can import into any compatible Bitcoin wallet
 to create a watch-only wallet (Electrum for example) that you can use to monitor your Bitcoin Core balance.
 
 :warning: this means that your Bitcoin Core wallet cannot send funds on its own (since it cannot access private keys to sign transactions).
@@ -86,7 +86,7 @@ $ bitcoin-cli -named createwallet wallet_name=eclair disable_private_keys=true b
 
 Copy `eclair-signer.conf` to your Eclair data directory but do not change `eclair.bitcoind.wallet`, and restart Eclair.
 
-`eclair-cli getdescriptors --account=0` will return public wallet descriptors in a format that is compatible with Bitcoin Core, and that you can import with `bitcoin-cli -rpcwallet=eclair importdescriptors`
+`eclair-cli getdescriptors` will return public wallet descriptors in a format that is compatible with Bitcoin Core, and that you can import with `bitcoin-cli -rpcwallet=eclair importdescriptors`
 This is an example of descriptors generated by Eclair:
 
 ```json
@@ -109,7 +109,7 @@ This is an example of descriptors generated by Eclair:
 You can generate the descriptors with your Eclair node and import them into a Bitcoin node with the following commands:
 
 ```shell
-$ eclair-cli getdescriptors --account=0 | jq --raw-output -c > descriptors.json
+$ eclair-cli getdescriptors | jq --raw-output -c > descriptors.json
 $ cat descriptors.json | xargs -0 bitcoin-cli -rpcwallet=eclair importdescriptors
 ```
 

eclair-node/src/main/scala/fr/acinq/eclair/api/handlers/OnChain.scala

@@ -72,8 +72,8 @@ trait OnChain {
   }
 
   val getmasterxpub: Route = postRequest("getmasterxpub") { implicit t =>
-    formFields("account".as[Long]) { account =>
-      val xpub = this.eclairApi.getOnchainMasterPubKey(account)
+    formFields("account".as[Long].?) { account_opt =>
+      val xpub = this.eclairApi.getOnchainMasterPubKey(account_opt.getOrElse(0L))
       complete(new JObject(List("xpub" -> JString(xpub))))
     }
   }