Crash on 404

[rklados]

When sending the results back to the main thread on a URL that responds with an error such as 404, the plugin will crash the entire application. The issue seems to be with the following call:

[self performSelectorOnMainThread:@selector(downloadCompleteWithError:)
withObject:[error description] waitUntilDone:YES];

commenting this out allows the application to fail more gracefully when encountering a page with error.