[gnome-characters] build: Ignore errors when including git.mk from Makefile.am

[Daiki Ueno <dueno src gnome org>]

commit 4d796d05abc4e9aa90a8ba880e0f2e411e6e7759
Author: Daiki Ueno <dueno src gnome org>
Date:   Mon Nov 24 17:41:10 2014 +0900

    build: Ignore errors when including git.mk from Makefile.am
    
    To prevent git.mk from being included in the distribution tarball, use
    "-include" instead of "include".

 Makefile.am       |    2 +-
 tests/Makefile.am |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/Makefile.am b/Makefile.am
index 0e3955d..4d1467c 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -49,4 +49,4 @@ clean-local:
 
 EXTRA_DIST = $(PACKAGE_NAME).spec
 
-include $(top_srcdir)/git.mk
+-include $(top_srcdir)/git.mk
diff --git a/tests/Makefile.am b/tests/Makefile.am
index ff7b475..dfc028d 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -30,4 +30,4 @@ else
 EXTRA_DIST += testutil.py $(dogtail_tests)
 endif
 
-include $(top_srcdir)/git.mk
+-include $(top_srcdir)/git.mk