[seahorse] Use git.mk for the generated gettext m4s

[Niels De Graef <nielsdg src gnome org>]

commit 31c65503d073d0e37eeaccb6d59d8220bcc4d990
Author: Niels De Graef <nielsdegraef gmail com>
Date:   Wed Sep 27 14:51:30 2017 +0200

    Use git.mk for the generated gettext m4s

 Makefile.am |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/Makefile.am b/Makefile.am
index ba9527b..d0f3a1a 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -26,7 +26,8 @@ EXTRA_DIST = \
 MAINTAINERCLEANFILES = \
        $(GITIGNORE_MAINTAINERCLEANFILES_TOPLEVEL) \
        $(GITIGNORE_MAINTAINERCLEANFILES_MAKEFILE_IN) \
-       $(GITIGNORE_MAINTAINERCLEANFILES_M4_LIBTOOL)
+       $(GITIGNORE_MAINTAINERCLEANFILES_M4_LIBTOOL) \
+       $(GITIGNORE_MAINTAINERCLEANFILES_M4_GETTEXT)
 
 DISTCHECK_CONFIGURE_FLAGS = \
     --disable-scrollkeeper \