test: add rescan_utxos in MiniWallet's initialization

this simplifies usage when MiniWallet is used with a pre-mined chain.

test/functional/p2p_permissions.py

@@ -26,7 +26,6 @@ class P2PPermissionsTests(BitcoinTestFramework):
 
     def run_test(self):
         self.wallet = MiniWallet(self.nodes[0])
-        self.wallet.rescan_utxos()
 
         self.check_tx_relay()