Fix spend public key for new check in upstream construct_tx (#15)

(cherry picked from commit 2ab30fbdb4be3bd182259853c120c7b92f819184)

src/backend.cpp

@@ -1540,7 +1540,7 @@ namespace lwsf { namespace internal { namespace backend
   cryptonote::account_keys wallet::get_primary_keys() const
   {
     return {
-      {primary.view.pub, primary.spend.pub}, primary.spend.sec, primary.view.sec
+      {primary.spend.pub, primary.view.pub}, primary.spend.sec, primary.view.sec
     }; 
   }
 

src/wallet.cpp

@@ -1576,6 +1576,7 @@ namespace lwsf { namespace internal
 
             std::unordered_map<crypto::public_key, cryptonote::subaddress_index> subs;
             std::vector<cryptonote::tx_source_entry> sources;
+            subs.emplace(change_account.m_spend_public_key, cryptonote::subaddress_index{subaddr_account, 0});
             for (const auto& spend : spending)
             {
               const auto& source = spend.second->receives.at(spend.first);