accountcombobox: only show username if different from best alias

This follow changes from lrc fixing getBestId.

Change-Id: I6ef298dfbcac9095cd5557c7b1d3caf42c0c3f3e

src/mainview/components/AccountComboBox.qml

@@ -158,7 +158,7 @@ Label {
                 Layout.fillWidth: true
                 Layout.alignment: Qt.AlignLeft | Qt.AlignVCenter
 
-                visible: text.length
+                visible: text.length && text != userAliasText.text
 
                 text:  AccountListModel.data(AccountListModel.index(0,0),
                                              AccountList.Username)

src/mainview/components/AccountItemDelegate.qml

@@ -79,7 +79,7 @@ ItemDelegate {
                 Layout.fillWidth: true
                 Layout.alignment: Qt.AlignLeft | Qt.AlignVCenter
 
-                visible: text.length
+                visible: text.length && Alias != Username
 
                 text: Username
                 font.pointSize: JamiTheme.textFontSize