update grunt clean-certs
update grunt clean-certs

clean-certs now again also the removes the certs for the pzh, which after
a recent change are stored in a different path.

Jira-issue: WP-778

webinos/Webinos-Platform,hansmy/Webinos-Platform,krishnabangalore/Webinos-Platform,webinos/Webinos-Platform,webinos/Webinos-Platform,hansmy/Webinos-Platform,hansmy/Webinos-Platform,hansmy/Webinos-Platform,hansmy/Webinos-Platform,hansmy/Webinos-Platform,krishnabangalore/Webinos-Platform,krishnabangalore/Webinos-Platform,krishnabangalore/Webinos-Platform,webinos/Webinos-Platform,krishnabangalore/Webinos-Platform,hansmy/Webinos-Platform,webinos/Webinos-Platform,krishnabangalore/Webinos-Platform,hansmy/Webinos-Platform,webinos/Webinos-Platform,webinos/Webinos-Platform,hansmy/Webinos-Platform,krishnabangalore/Webinos-Platform,krishnabangalore/Webinos-Platform,webinos/Webinos-Platform,webinos/Webinos-Platform,krishnabangalore/Webinos-Platform