manibuilder: Allow differing uid to fix local Git access

Change-Id: Iae06908a2cb2e0c55245a14600590ad0c6d91146
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.sourcearcade.org/c/flashprog/+/388
diff --git a/util/manibuilder/Dockerfile.git b/util/manibuilder/Dockerfile.git
index 10d7aa6..8794c50 100644
--- a/util/manibuilder/Dockerfile.git
+++ b/util/manibuilder/Dockerfile.git
@@ -1,6 +1,7 @@
 FROM alpine/git
 
 RUN	apk add git-daemon
+RUN	git config --global --add safe.directory /git/flashprog.git
 EXPOSE	9418
 VOLUME	["/git/flashprog.git"]
 CMD	["daemon", "--reuseaddr", "--export-all", "--base-path=/git", "/git/flashprog.git"]