Make hard-coded max response configurable:

- see discussion started by @schmaker@schmaker.eu at https://schmaker.eu/display/c83e3896-1265-a3d6-0ab5-a78119129626
- this allows servers with lower RAM amount to still run without OOMs (or much lesser)

src/Network/HTTPClient/Factory/HttpClient.php

@@ -123,7 +123,7 @@ class HttpClient extends BaseFactory
 		$resolver->setMaxRedirects(10);
 		$resolver->setRequestTimeout(10);
 		// if the file is too large then exit
-		$resolver->setMaxResponseDataSize(1000000);
+		$resolver->setMaxResponseDataSize($this->config->get('system', 'max_response_data_size', 1000000));
 		// Designate a temporary file that will store cookies during the session.
 		// Some websites test the browser for cookie support, so this enhances results.
 		$resolver->setCookieJar(System::getTempPath() .'/resolver-cookie-' . Strings::getRandomName(10));