[tests] Set -deprecatedrpc=accounts in tests

Future commits will deprecate the accounts RPC methods, arguments and
return objects. Set the -deprecatedrpc=accounts switch now so tests
don't break in intermediate commits.

test/functional/wallet_labels.py

@@ -21,7 +21,7 @@ class WalletLabelsTest(BitcoinTestFramework):
     def set_test_params(self):
         self.setup_clean_chain = True
         self.num_nodes = 1
-        self.extra_args = [[]]
+        self.extra_args = [['-deprecatedrpc=accounts']]
 
     def run_test(self):
         node = self.nodes[0]