Make sure 'jetpack_client_id' is available in the response of getBlogOptions before reading and storing it.
Test that blogOptions String is a valid JSON object encoded string, and set default to '{}' (empty object) in case of errors.
Merge pull request #1056 from wordpress-mobile/issue/1055-jetpack_client_id-getBlogOptions

Check the presence of 'jetpack_client_id' in the response of getBlogOptions before reading it