transactionInfo: use empty str when fee=0

components/HistoryTable.qml

@@ -383,7 +383,7 @@ ListView {
             Column {
                 anchors.top: parent.top
                 width: 148
-                visible: isOut
+                visible: isOut && fee != ""
                 Text {
                     anchors.left: parent.left
                     font.family: "Arial"

src/libwalletqt/TransactionInfo.cpp

@@ -38,6 +38,8 @@ QString TransactionInfo::displayAmount() const
 
 QString TransactionInfo::fee() const
 {
+    if(m_pimpl->fee() == 0)
+        return "";
     return WalletManager::instance()->displayAmount(m_pimpl->fee());
 }