[gnome-flashback] update MAINTAINERCLEANFILES

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 7f6164ce9cb7f0eb0911bb15e9a792549cd1edb1
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Sun Mar 25 16:02:11 2018 +0300

    update MAINTAINERCLEANFILES

 Makefile.am |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/Makefile.am b/Makefile.am
index 70cb5a3..7b81cd5 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -10,6 +10,7 @@ SUBDIRS = \
 MAINTAINERCLEANFILES = \
        $(GITIGNORE_MAINTAINERCLEANFILES_TOPLEVEL) \
        $(GITIGNORE_MAINTAINERCLEANFILES_MAKEFILE_IN) \
+       $(GITIGNORE_MAINTAINERCLEANFILES_M4_GETTEXT) \
        $(GITIGNORE_MAINTAINERCLEANFILES_M4_LIBTOOL) \
        `find "$(srcdir)/m4" -type f -name "*.m4" -print` \
        $(srcdir)/ABOUT-NLS \