test: add coverage for unknown wallet flag in setwalletflag

Author: brunoerg

test/functional/wallet_avoidreuse.py

@@ -120,6 +120,8 @@ def test_persistence(self):
         assert_raises_rpc_error(-8, "Wallet flag is already set to false", self.nodes[0].setwalletflag, 'avoid_reuse', False)
         assert_raises_rpc_error(-8, "Wallet flag is already set to true", self.nodes[1].setwalletflag, 'avoid_reuse', True)
 
+        assert_raises_rpc_error(-8, "Unknown wallet flag: abc", self.nodes[0].setwalletflag, 'abc', True)
+
         # Create a wallet with avoid reuse, and test that disabling it afterwards persists
         self.nodes[1].createwallet(wallet_name="avoid_reuse_persist", avoid_reuse=True)
         w = self.nodes[1].get_wallet_rpc("avoid_reuse_persist")