Fixes#1747
MediaWiki on Debian seems to store all uploaded files under images/
folder. The administrator can enable additional file types. In the
default configuration, only image files are permitted.
Manually tested that backup/restore works irrespective of file type.
Signed-off-by: Joseph Nuthalapati <njoseph@riseup.net>
Reviewed-by: Sunil Mohan Adapa <sunil@medhas.org>