chore: check if WEBP is supported (#6073)

src/RunGui.cpp

@@ -11,6 +11,7 @@
 #include "singletons/Settings.hpp"
 #include "singletons/Updates.hpp"
 #include "util/CombinePath.hpp"
+#include "util/SelfCheck.hpp"
 #include "util/UnixSignalHandler.hpp"
 #include "widgets/dialogs/LastRunCrashDialog.hpp"
 
@@ -257,6 +258,8 @@ void runGui(QApplication &a, const Paths &paths, Settings &settings,
     }
 #endif
 
+    selfcheck::checkWebp();
+
     updates.deleteOldFiles();
 
     // Clear the cache 1 minute after start.