Configurable cookie lifetime

+++ b/eu_cookie_compliance.module
@@ -184,6 +184,7 @@ function eu_cookie_compliance_page_attachments(&$attachments) {
+      'cookie_lifetime'      => !empty($config->get('cookie_lifetime')) ? $config->get('cookie_lifetime') : '100'

I'm against this internal checks. Use a hook_update_N() and fill this config and just do a get only.

For the rest looks ok.

We have such checks in the code already (for example on line 186), and it's a common code for Drupal sites. I would say this does not require an update hook. I'll look into why this is failing and provide an updated patch.

-

The field title was a bit verbose, so I named it "Cookie Lifetime" and moved your title into the description. I also added $this->t() instead of just t() for translation and placed the field inside the Advanced section of the form. Otherwise looks great! Here's the updated patch.