meta-ci: allow empty commits

A revert came through recently that resulted in an empty commit. Instead
of failing CI on that, just allow it to go through.

Change-Id: Ie4fc40ed7021a1f27dffbabde9c23657684ae132
Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
diff --git a/jenkins/run-meta-ci b/jenkins/run-meta-ci
index 124022c..023b8de 100755
--- a/jenkins/run-meta-ci
+++ b/jenkins/run-meta-ci
@@ -42,4 +42,4 @@
 
 # Create a dummy commit so code update will pick it up
 cd openbmc
-git add -A && git commit -m "Dummy commit to cause code update"
+git add -A && git commit --allow-empty -m "Dummy commit to cause code update"