Check for Web support in v-add-webmail

bin/v-add-webmail

@@ -44,6 +44,7 @@ get_user_ip
 check_args '3' "$#" 'USER DOMAIN [RESTART]'
 is_format_valid 'user' 'domain'
 is_system_enabled "$MAIL_SYSTEM" 'MAIL_SYSTEM'
+is_system_enabled "$WEB_SYSTEM" 'WEB_SYSTEM'
 is_object_valid 'user' 'USER' "$user"
 is_object_unsuspended 'user' 'USER' "$user"
 is_object_valid 'mail' 'DOMAIN' "$domain"