Enable images upload in user profile

[renoirb]

The user profile has been modified to forbid image uploads. The reason we did it is that the SocialProfile MediaWiki Extension is using a different file upload system than the rest of the MediaWiki code base.

While the rest of MediaWiki install allows file uploads, we store them in an external cloud storage service. In the case of this specific extension, we had to set in place storage mounts across a number of VMs and it was decided to be not worth spending computing resource for only one feature that isn’t critical to our site.