Fix display of automation errors on startup

The wxLogger isn't created until it's needed by the main thread, so any
errors logged on a background thread before the logger was first used on
the main thread were simply being discarded. Fix this by forcing the
creation of the logger very early in the startup process.

aegisub/src/main.cpp

@@ -112,6 +112,10 @@ bool AegisubApp::OnInit() {
 	SetAppName("aegisub");
 #endif
 
+	// The logger isn't created on demand on background threads, so force it to
+	// be created now
+	(void)wxLog::GetActiveTarget();
+
 	// Set the global locale to the utf-8 version of the current locale
 	std::locale::global(boost::locale::generator().generate(""));
 	boost::filesystem::path::imbue(std::locale());