Starts support branch and improve .gitreview

Change-Id: I10435921ed6b62396e6144142c0a70ded42c12d8
diff --git a/.gitreview b/.gitreview
index ac9f466..0ca3998 100644
--- a/.gitreview
+++ b/.gitreview
@@ -3,3 +3,4 @@
 port=29418
 project=igmpproxy.git
 defaultremote=origin
+defaultbranch=igmpproxy-1.2