* imapnotify: enable STARTTLS if enabled in email account config
Since version 2.3.10 goimapnotify supports starttls. In version 2.3.11 a
typo in the settings was fixed, using tlsOptions.starttls to enable it.
This commit enables starttls in the goimapnotify config file if it is
enabled in the email account's imap settings.
* imapnotify: test generated config file
Compare the generated service config file with a manually verified
sample.