doc: clarify entry for supporting pg_service.conf.

Author: rouilj

CHANGES.txt

@@ -99,10 +99,11 @@ Features:
   items when using list/table. Add pragma display_header to print
   headers for display command. Header displays designator and
   retired/active status. (John Rouillard)
-- support config.ini rdbms option 'service'. Allow use of a
-  PostgreSQL connection service file for configuring database on a
-  per-tracker basis. Also replaces use of PGSERVICE env variable for
-  single instance trackers. (From ML question by ivanov. John Rouillard)
+- issue2551299 - support config.ini rdbms option 'service'. Allow use
+  of a PostgreSQL connection service file (pg_service.conf) for
+  configuring database on a per-tracker basis. Also replaces use of
+  PGSERVICE env variable for single instance trackers. (From ML
+  question by ivanov. John Rouillard)
 
 2023-07-13 2.3.0