[gnome-usage] Update POTFILES.skip

[Piotr Drąg <piotrdrag src gnome org>]

commit fd9508488c4fe782766705f86b3982baeb7e500f
Author: Piotr Drąg <piotrdrag gmail com>
Date:   Wed Feb 22 18:56:25 2017 +0100

    Update POTFILES.skip
    
    If these files don’t have strings that are visible to the user and
    therefore you don’t want to translate them, they need to be in
    po/POTFILES.skip. Otherwise i18n tools complain about files missing
    from po/POTFILES.in.

 po/POTFILES.skip |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/po/POTFILES.skip b/po/POTFILES.skip
index b35d01b..379cb5c 100644
--- a/po/POTFILES.skip
+++ b/po/POTFILES.skip
@@ -1,6 +1,9 @@
 # List of source files that should *not* be translated.
 # Please keep this file sorted alphabetically.
 external/egg/egg-animation.c
+external/egg/egg-date-time.c
+external/egg/egg-file-chooser-entry.c
+external/egg/egg-search-bar.c
 src/application.c
 src/cpu-sub-view.c
 src/data-view.c