Update gitreview for v2.11, merge with branch=voltha-2.11 by default

Change-Id: Iaf736189e58e88d88445670a625f3f0b2a0c5dc7
diff --git a/.gitreview b/.gitreview
index ac9f466..376bde1 100644
--- a/.gitreview
+++ b/.gitreview
@@ -3,3 +3,4 @@
 port=29418
 project=igmpproxy.git
 defaultremote=origin
+defaultbranch=voltha-2.11