.gitreview: update repo url to new location

Old files was a leftover from split out of openbsc.

Change-Id: Ifefb345df6c00aadee0ccc3c59796dba590a9f32
diff --git a/.gitreview b/.gitreview
index ee67509..560ddef 100644
--- a/.gitreview
+++ b/.gitreview
@@ -1,3 +1,3 @@
 [gerrit]
 host=gerrit.osmocom.org
-project=openbsc
+project=osmo-sgsn