Fix Ogre being initialised twice

apps/launcher/graphicspage.cpp

@@ -137,6 +137,7 @@ bool Launcher::GraphicsPage::setupSDL()
         return false;
     }
 
+    screenComboBox->clear();
     for (int i = 0; i < displays; i++)
     {
         screenComboBox->addItem(QString(tr("Screen ")) + QString::number(i + 1));
@@ -149,7 +150,7 @@ bool Launcher::GraphicsPage::loadSettings()
 {
     if (!setupSDL())
         return false;
-    if (!setupOgre())
+    if (!mOgre && !setupOgre())
         return false;
 
     if (mGraphicsSettings.value(QString("Video/vsync")) == QLatin1String("true"))

components/ogreinit/ogreinit.cpp

@@ -94,6 +94,8 @@ namespace OgreInit
 
     Ogre::Root* OgreInit::init(const std::string &logPath)
     {
+        if (mRoot)
+            throw std::runtime_error("OgreInit was already initialised");
 
         #ifndef ANDROID
         // Set up logging first