A thrown exception is not an error, per se, as one might request an
email to see if it exists. It's the responsibility of the caller to
determine if a request failure warrants logging an error.

Based on findings from phpcs and phpstan.

Issue #3160290 by arnested: Warning: Invalid argument supplied for foreach() in apsis_mail_form_user_form_alter() (line 58 of apsis_mail.module)

In 2bee363d we made sure the configured
cache lifetime _must_ be an integer (using `is_int()`).

Unfortunately the form submits a string even if the value was an
integer and that git stored in the config system as string.

This change:

* converts the submitted value to an integer before storing it
  in the config system
* ensures the configured value is a numeric instead of an integer before
  converting it to integer and using it
* updates already stored numeric strings to integers in the config system

Revert already configured cache lifetime option to match the change in 33d3eff1.

Also harden the lookup of the config value in case the update hook is
not executed or got corrupted in some other way.

Jose Jiménez authored Jun 09, 2020 and Thomas Fini Hansen committed Jun 09, 2020

Issue #3134707 by jjcarrion: Warning: count(): Parameter must be an array or an object that implements Countable in Drupal\apsis_mail\Form\SubscribeForm->submitForm()