Merge pull request #7565 from nextcloud/backport/7564/stable-3.15

[stable-3.15] no transparent background for main ApplicationWindow

Author: mgallien

src/gui/tray/MainWindow.qml

@@ -36,7 +36,6 @@ ApplicationWindow {
     width:      Systray.useNormalWindow ? Style.trayWindowHeight : Style.trayWindowWidth
     height:     Style.trayWindowHeight
     flags:      Systray.useNormalWindow ? Qt.Window : Qt.Dialog | Qt.FramelessWindowHint
-    color: 'transparent'
 
     readonly property int maxMenuHeight: Style.trayWindowHeight - Style.trayWindowHeaderHeight - 2 * Style.trayWindowBorderWidth