ux: disable combobox if only one account is present

Change-Id: I1d842cc9a1cf64e4c1bf02b4744ff06be78780e3
Reviewed-by: Andreas Traczyk <andreas.traczyk@savoirfairelinux.com>

currentaccountcombobox.cpp

@@ -176,7 +176,9 @@ void
 CurrentAccountComboBox::mousePressEvent(QMouseEvent* mouseEvent)
 {
     if (!gearLabel_.frameGeometry().contains(mouseEvent->localPos().toPoint())) {
+        if (count() > 1) {
             QComboBox::mousePressEvent(mouseEvent);
+        }
     } else {
         emit settingsButtonClicked();
     }