Strict mode checking - no way to forget detaching now.

And if we forget to attach, boom. Hopefully I caught all of them.

Core/WebServer.cpp

@@ -314,6 +314,8 @@ static void ForwardDebuggerRequest(const http::Request &request) {
 static void ExecuteWebServer() {
 	SetCurrentThreadName("HTTPServer");
 
+	AndroidJNIThreadContext context;  // Destructor detaches.
+
 	auto http = new http::Server(new NewThreadExecutor());
 	http->RegisterHandler("/", &HandleListing);
 	// This lists all the (current) recent ISOs.