bump up time out for a cell node to 3 minutes

Change-Id: I531d799ee136d4ac3bed30f0a3b0714f04587c71
diff --git a/tools/test/bin/onos-verify-cell b/tools/test/bin/onos-verify-cell
index 55c2b32..72a23df 100755
--- a/tools/test/bin/onos-verify-cell
+++ b/tools/test/bin/onos-verify-cell
@@ -9,7 +9,7 @@
 let err=0
 
 for node in $OCT $OCN $(env | sort | egrep "^OC[0-9]+" | cut -d= -f2); do
-    for i in 1 2 3 4 5 6; do
+    for i in {1..18}; do
         printf "%s: " $node; ssh -n -q -o StrictHostKeyChecking=no -o PasswordAuthentication=no -o ConnectTimeout=10 $ONOS_USER@$node hostname
         if [ $? -eq 0 ]; then
             let err=0