settings: remove obsolete eos-browser settings
settings: remove obsolete eos-browser settings

eos-browser appears to have been a rebranded version of Epiphany. It
seems to have been removed from the OS before May 2014 at the latest,
since https://phabricator.endlessm.com/T2431 shows its repo being a
candidate for removal then.

endlessm/eos-theme