[QA] Fix typo in fundrawtransaction test

Ping @jnewbery introduced on bitcoin/bitcoin@dab804c

Author: NicolasDorier

test/functional/fundrawtransaction.py

@@ -472,7 +472,7 @@ def run_test(self):
         rawTx = self.nodes[1].createrawtransaction(inputs, outputs)
         # fund a transaction that requires a new key for the change output
         # creating the key must be impossible because the wallet is locked
-        assert_raises_jsonrpc(-4, "Insufficient funds", self.nodes[1].fundrawtransaction, rawtx)
+        assert_raises_jsonrpc(-4, "Keypool ran out, please call keypoolrefill first", self.nodes[1].fundrawtransaction, rawTx)
 
         #refill the keypool
         self.nodes[1].walletpassphrase("test", 100)