Use COINBASE_MATURITY constant in functional tests.

test/functional/wallet_multiwallet.py

@@ -14,6 +14,7 @@ import stat
 import time
 
 from test_framework.authproxy import JSONRPCException
+from test_framework.blocktools import COINBASE_MATURITY
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.test_node import ErrorMatch
 from test_framework.util import (
@@ -229,7 +230,7 @@ class MultiWalletTest(BitcoinTestFramework):
         assert_raises_rpc_error(-19, "Wallet file not specified", node.getwalletinfo)
 
         w1, w2, w3, w4, *_ = wallets
-        node.generatetoaddress(nblocks=101, address=w1.getnewaddress())
+        node.generatetoaddress(nblocks=COINBASE_MATURITY + 1, address=w1.getnewaddress())
         assert_equal(w1.getbalance(), 100)
         assert_equal(w2.getbalance(), 0)
         assert_equal(w3.getbalance(), 0)