component/postfix: use openssl 1.1 again

Now that we updated postfix, we can use default openssl

According to http://www.postfix.org/announcements/postfix-3.1.2.html

> Fixed with Postfix 3.1.2:
> Changes to make Postfix build with OpenSSL 1.1.0.
4 jobs for fix/seleniumserver-capri-testnode-2 in 0 seconds
Status Job ID Name Coverage
  External
passed SlapOS.SlapRunner.ResilienceTest-Master

failed SlapOS.SlapRunner.ResilienceTest-Master.ERP5

00:27:46

canceled SlapOS.SoftwareReleases.IntegrationTest-Jerome-WIP2

failed SlapOS.SoftwareReleases.IntegrationTest-Master.Python3

08:39:45