test: rpc_createmultisig, remove manual wallet initialization

There is no need to manually initialize the wallets within the test
case. The test framework already initializes them when `_requires_wallet`
is true.

test/functional/rpc_createmultisig.py

@@ -32,6 +32,7 @@ class RpcCreateMultiSigTest(BitcoinTestFramework):
         self.setup_clean_chain = True
         self.num_nodes = 3
         self.supports_cli = False
+        self.enable_wallet_if_possible()
 
     def get_keys(self):
         self.pub = []
@@ -51,7 +52,6 @@ class RpcCreateMultiSigTest(BitcoinTestFramework):
         self.wallet = MiniWallet(test_node=node0)
 
         if self.is_bdb_compiled():
-            self.import_deterministic_coinbase_privkeys()
             self.check_addmultisigaddress_errors()
 
         self.log.info('Generating blocks ...')