fix: get_public_keys method of p2pk wallets

lib/wallet.py

@@ -1266,6 +1266,10 @@ class P2PK_Wallet(Abstract_Wallet):
         pubkey_list = self.change_pubkeys if c else self.receiving_pubkeys
         return pubkey_list[i]
 
+    def get_public_keys(self, address):
+        sequence = self.get_address_index(address)
+        return [self.get_pubkey(*sequence)]
+
     def get_pubkey_index(self, pubkey):
         if pubkey in self.receiving_pubkeys:
             return False, self.receiving_pubkeys.index(pubkey)