[gucharmap] build: Fix Makevars

[Christian Persch <chpe src gnome org>]

commit e4387816a5bc4cbe99cf075be2ec367f54681333
Author: Christian Persch <chpe src gnome org>
Date:   Wed Aug 8 18:42:22 2018 +0200

    build: Fix Makevars
    
    gucharmap does use message contexts.
    
    https://gitlab.gnome.org/GNOME/gucharmap/issues/11

 po/Makevars | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/po/Makevars b/po/Makevars
index 0fbff945..66627242 100644
--- a/po/Makevars
+++ b/po/Makevars
@@ -67,7 +67,7 @@ EXTRA_LOCALE_CATEGORIES =
 # context.  Possible values are "yes" and "no".  Set this to yes if the
 # package uses functions taking also a message context, like pgettext(), or
 # if in $(XGETTEXT_OPTIONS) you define keywords with a context argument.
-USE_MSGCTXT = no
+USE_MSGCTXT = yes
 
 # These options get passed to msgmerge.
 # Useful options are in particular: