Increase timeout for jenkins startup

Docker image pull for jenkins image can take more than
2 minutes, so it would be better to increase wait time.

Change-Id: Ia8a49747f3517e2189bb00a6ffff6a195782db41
Related-bug: #PROD-25653 (PROD:25653)
diff --git a/config-drive/master_config.yaml b/config-drive/master_config.yaml
index 3e68c74..91c7cd8 100644
--- a/config-drive/master_config.yaml
+++ b/config-drive/master_config.yaml
@@ -130,7 +130,7 @@
       jport=$(salt-call --out=text pillar.get jenkins:master:http:port | awk '{print $2}')
       jport=${jport:-8081}
       wait_time=0
-      until [[ $(curl -sL -w "%{http_code}" localhost:$jport -o /dev/null) == 200 ]] || [ $wait_time -eq 15 ]; do
+      until [[ $(curl -sL -w "%{http_code}" localhost:$jport -o /dev/null) == 200 ]] || [ $wait_time -eq 20 ]; do
         sleep $(( wait_time++ ))
       done
     }