OP#501 adding variables and place holders for certs

templates/ssl_ca_cert.erb

@@ -1,3 +1,3 @@
-<% unless @ne_ssl_ca_cert_pem.nil -%>
+<% unless @ne_ssl_ca_cert_pem.undef -%>
 <%= @ne_ssl_ca_cert_pem %>
 <% end -%>

templates/ssl_cert.erb

@@ -1,3 +1,3 @@
-<% unless @ne_ssl_cert_pem.nil -%>
+<% unless @ne_ssl_cert_pem.undef -%>
 <%= @ne_ssl_cert_pem %>
 <% end -%>

templates/ssl_privatekey.erb

@@ -1,3 +1,3 @@
-<% unless @ne_ssl_privatekey_pem.nil -%>
+<% unless @ne_ssl_privatekey_pem.undef -%>
 <%= @ne_ssl_privatekey_pem %>
 <% end -%>