Merge #724: bitcoind: don't set load_on_startup when loading watchonly wallet

e072e896c7dc744147c38a7d36d9eedd413399fa bitcoind: don't set load_on_startup when loading watchonly wallet (Antoine Poinsot)

Pull request description:

  This was necessary to transition wallets that were created without this flag, but since v2 they are always created with it so this is redundant: it'd unnecessarily try to update the flag over and over again on bitcoind's side, always with the same value.

  Fixes #641.

ACKs for top commit:
  edouardparis:
    utACK e072e896c7dc744147c38a7d36d9eedd413399fa

Tree-SHA512: 517cdb2ee44f9237325dee76646aa84decc5bfb8c375798ebf6a8729c3acbe1661afb61eb69901a284bd6074b2b090115d145ec2a87cba1d434e6f77e78cbb14

src/bitcoin/d/mod.rs

@@ -652,10 +652,7 @@ impl BitcoinD {
         }
         let res = self.make_fallible_node_request(
             "loadwallet",
-            &params!(
-                Json::String(self.watchonly_wallet_path.clone()),
-                Json::Bool(true), // load_on_startup
-            ),
+            &params!(Json::String(self.watchonly_wallet_path.clone()),),
         );
         match res {
             Err(BitcoindError::Server(jsonrpc::Error::Rpc(ref e))) => {