test: add rescan_utxos in MiniWallet's initialization

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

test/functional/mining_prioritisetransaction.py

@@ -106,7 +106,6 @@ class PrioritiseTransactionTest(BitcoinTestFramework):
 
     def run_test(self):
         self.wallet = MiniWallet(self.nodes[0])
-        self.wallet.rescan_utxos()
 
         # Test `prioritisetransaction` required parameters
         assert_raises_rpc_error(-1, "prioritisetransaction", self.nodes[0].prioritisetransaction)