v1.19.4

Changes

• Legacy service/action notifiers can now be specified with or without the "notify." prefix. It used to be they only worked without the prefix. Updated docs.
• Restrict certain templates from self-referencing the alert2 entity, to conservatively prevent reference loops. This includes generator, friendly_name, condition, delay_on_secs, condition_on, condition_off and any of the threshold config parameters. If someone has a use case for self-referencing with those parameters, let's chat.
• Bugfix: If the display_msg config parameter self-referenced the Alert2 entity, the reference-loop detection logic was faulty. I removed the logic. Still, be careful if self-referencing in display_msg. It may be possible to create reference loops.