Updated the base_url for all images

[mklb]

http://imgobject.com was decommissioned in late 2012. Since the last weekend the domain is down. So the URLs won´t work anymore.

For more information check out my conversation with @themoviedb on Twitter: https://twitter.com/themoviedb/status/568519156502368258

[Alexey-Lukin]

+1 for merging this asap