[eog] help: Remove deprecated/outdated Bulgarian translation

[Felix Riemann <friemann src gnome org>]

commit 46ba99c18b0840cf4939c6d5b811081add1e6b00
Author: Felix Riemann <friemann gnome org>
Date:   Sun Jan 7 18:23:37 2018 +0100

    help: Remove deprecated/outdated Bulgarian translation
    
    The translation is still in the OMF/Scrollkeeper XML format. It apparently
    never made the migration to gnome-doc-utils or Mallard. Due to this it was
    never included since the migration to gnome-doc-utils in 2006.
    The switch to Meson will unnecessarily include it in the tarballs though.

 help/bg/eog-bg.xml |   18 --
 help/bg/eog.xml    |  565 ----------------------------------------------------
 help/bg/legal.xml  |    9 -
 3 files changed, 0 insertions(+), 592 deletions(-)