Play cards only with double left click

Fix #340

cockatrice/src/carditem.cpp

@@ -358,6 +358,7 @@ void CardItem::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
 
 void CardItem::mouseDoubleClickEvent(QGraphicsSceneMouseEvent *event)
 {
+    if (event->buttons() == Qt::LeftButton){
         if (settingsCache->getDoubleClickToPlay()) {
             if (revealedCard)
                 zone->removeCard(this);
@@ -365,6 +366,7 @@ void CardItem::mouseDoubleClickEvent(QGraphicsSceneMouseEvent *event)
                 playCard(event->modifiers().testFlag(Qt::ShiftModifier));
         }
         event->accept();
+    }
 }