No longer shutdown after encrypting the wallet

Since the database environment is flushed, closed, and reopened during
EncryptWallet, there is no need to shut down the software anymore.

test/functional/wallet_bumpfee.py

@@ -36,8 +36,7 @@ class BumpFeeTest(BitcoinTestFramework):
 
     def run_test(self):
         # Encrypt wallet for test_locked_wallet_fails test
-        self.nodes[1].node_encrypt_wallet(WALLET_PASSPHRASE)
-        self.start_node(1)
+        self.nodes[1].encryptwallet(WALLET_PASSPHRASE)
         self.nodes[1].walletpassphrase(WALLET_PASSPHRASE, WALLET_PASSPHRASE_TIMEOUT)
 
         connect_nodes_bi(self.nodes, 0, 1)