remove dependency injection from systemtrayicon

as it was used as experiment only
fix compilation warning about unchecked switch case

src/main.cpp

@@ -70,6 +70,8 @@ void logMessageHandler(QtMsgType type, const QMessageLogContext& ctxt, const QSt
         case QtFatalMsg:
             LogMsg += "Fatal";
             break;
+        default:
+            break;
     }
 
     LogMsg += ": " + msg + "\n";

src/widget/systemtrayicon.cpp

@@ -26,9 +26,8 @@
 #include <QDebug>
 #include "src/persistence/settings.h"
 
-SystemTrayIcon::SystemTrayIcon(Widget *parent)
+SystemTrayIcon::SystemTrayIcon()
 {
-    this->parent = parent;
     QString desktop = getenv("XDG_CURRENT_DESKTOP");
     if (desktop.isEmpty())
         desktop = getenv("DESKTOP_SESSION");

src/widget/systemtrayicon.h

@@ -22,7 +22,6 @@
 #define SYSTEMTRAYICON_H
 
 #include "systemtrayicon_private.h"
-#include "widget.h"
 #include <QObject>
 
 class QSystemTrayIcon;
@@ -32,7 +31,7 @@ class SystemTrayIcon : public QObject
 {
     Q_OBJECT
 public:
-    SystemTrayIcon(Widget *parent);
+    SystemTrayIcon();
     ~SystemTrayIcon();
     void setContextMenu(QMenu* menu);
     void show();
@@ -49,7 +48,6 @@ private:
 private:
     SystrayBackendType backendType;
     QSystemTrayIcon* qtIcon;
-    Widget *parent;
 
 #ifdef ENABLE_SYSTRAY_UNITY_BACKEND
     AppIndicator *unityIndicator;

src/widget/widget.cpp

@@ -119,6 +119,7 @@ void Widget::init()
     offlineMsgTimer = new QTimer();
     offlineMsgTimer->start(15000);
 
+    icon_size = 15;
     statusOnline = new QAction(this);
     statusOnline->setIcon(getStatusIcon(Status::Online, icon_size, icon_size));
     connect(statusOnline, &QAction::triggered, this, &Widget::setStatusOnline);
@@ -1693,7 +1694,7 @@ void Widget::onTryCreateTrayIcon()
     {
         if (QSystemTrayIcon::isSystemTrayAvailable())
         {
-            icon = new SystemTrayIcon(this);
+            icon = new SystemTrayIcon();
             updateIcons();
             trayMenu = new QMenu(this);
             QStyle *style = qApp->style();

src/widget/widget.h

@@ -183,7 +183,7 @@ private slots:
     void friendListContextMenu(const QPoint &pos);
 
 private:
-    const int icon_size = 15;
+    int icon_size;
 
 private:
     enum ActiveToolMenuButton {