[BUG][GUI] Cache unconfirmed_balance only for transparent outs

shield balance is already cached in unconfirmed_shielded_balance, which
is then added to unconfirmed_balance to get the total.

Github-Pull: #2102
Rebased-From: 149524f

src/interface/wallet.cpp

@@ -11,7 +11,7 @@ namespace interfaces {
     WalletBalances Wallet::getBalances() {
         WalletBalances result;
         result.balance = m_wallet.GetAvailableBalance();
-        result.unconfirmed_balance = m_wallet.GetUnconfirmedBalance();
+        result.unconfirmed_balance = m_wallet.GetUnconfirmedBalance(ISMINE_SPENDABLE_TRANSPARENT);
         result.immature_balance = m_wallet.GetImmatureBalance();
         result.have_watch_only = m_wallet.HaveWatchOnly();
         if (result.have_watch_only) {
@@ -26,4 +26,4 @@ namespace interfaces {
         return result;
     }
 
-} // namespace interfaces
+} // namespace interfaces