test: Remove wallet option from non-wallet tests

Review note: The changes are complete, because self.options.descriptors
is set to None in parse_args (test_framework.py).

A value of None implies -disablewallet, see the previous commit.

So if a call to add_wallet_options is missing, it will lead to a test
failure when the wallet is compiled in.

test/functional/wallet_implicitsegwit.py

@@ -39,6 +39,9 @@ def check_implicit_transactions(implicit_keys, implicit_node):
             assert(('receive', b_address) in tuple((tx['category'], tx['address']) for tx in txs))
 
 class ImplicitSegwitTest(BitcoinTestFramework):
+    def add_options(self, parser):
+        self.add_wallet_options(parser, descriptors=False)
+
     def set_test_params(self):
         self.num_nodes = 2
         self.supports_cli = False