Not compatible with Postgres 12 due to use of obsolete and now-removed def.adsrc

[chk-mk]

Steps to reproduce this issue

1. Try viewing a table on a postgres 12 DB

Current behavior

Nothing shown but errors in console:

ERROR: column def.adsrc does not exist

Expected behavior

Works.

Possible solution

Stop using adsrc or put a note that postgres 12 isn't supported.

See dbcli/pgcli#1058

Environment

• HeidiSQL version:
  10.2.0.5599 at least but most likely all.
• Database system and version:
  Postgres 12 beta1 and newer.

[ansgarbecker]

Using pg_get_expr(def.adbin, def.adrelid) from the next build on.

Thanks for the link to the pgcli issue - solution was easy this way.