Avoid doing non-trivial work in onCheckedChanged on settings page load

app/gui/SettingsView.qml

@@ -685,6 +685,9 @@ Flickable {
                     font.pointSize: 12
                     checked: prefs.unsupportedFps
                     onCheckedChanged: {
+                        // This is called on init, so only do the work if we've
+                        // actually changed the value.
+                        if (prefs.unsupportedFps != checked) {
                             prefs.unsupportedFps = checked
 
                             // The selectable FPS values depend on whether
@@ -692,6 +695,7 @@ Flickable {
                             fpsComboBox.reinitialize()
                         }
                     }
+                }
 
                 CheckBox {
                     id: enableMdns
@@ -699,6 +703,9 @@ Flickable {
                     font.pointSize: 12
                     checked: prefs.enableMdns
                     onCheckedChanged: {
+                        // This is called on init, so only do the work if we've
+                        // actually changed the value.
+                        if (prefs.enableMdns != checked) {
                             prefs.enableMdns = checked
 
                             // We must save the updated preference to ensure
@@ -712,6 +719,7 @@ Flickable {
                             }
                         }
                     }
+                }
 
                 CheckBox {
                     id: quitAppAfter