Make class variable const

src/gui/uithememanager.cpp

@@ -76,6 +76,9 @@ void UIThemeManager::initInstance()
 
 UIThemeManager::UIThemeManager()
     : m_useCustomTheme(Preferences::instance()->useCustomUITheme())
+#if (defined(Q_OS_UNIX) && !defined(Q_OS_MACOS))
+    , m_useSystemTheme(Preferences::instance()->useSystemIconTheme())
+#endif
 {
     const Preferences *const pref = Preferences::instance();
     if (m_useCustomTheme) {
@@ -87,10 +90,6 @@ UIThemeManager::UIThemeManager()
             applyPalette();
         }
     }
-
-#if (defined(Q_OS_UNIX) && !defined(Q_OS_MACOS))
-    m_useSystemTheme = pref->useSystemIconTheme();
-#endif
 }
 
 UIThemeManager *UIThemeManager::instance()

src/gui/uithememanager.h

@@ -64,6 +64,6 @@ private:
     mutable QHash<QString, QIcon> m_iconCache;
     const bool m_useCustomTheme;
 #if (defined(Q_OS_UNIX) && !defined(Q_OS_MACOS))
-    bool m_useSystemTheme;
+    const bool m_useSystemTheme;
 #endif
 };