add changelog entry

CHANGELOG.asciidoc

@@ -81,6 +81,7 @@ https://github.com/elastic/beats/compare/v6.2.3...master[Check the HEAD diff]
 - Commit registry writes to stable storage to avoid corrupt registry files. {issue}6792[6792]
 - Fix a data race between stopping and starting of the harverters. {issue}#6879[6879]
 - Fix a parsing issue in the syslog input for RFC3339 timestamp and time with nanoseconds. {pull}7046[7046]
+- Comply with PostgreSQL database name format {pull}7198[7198]
 
 *Heartbeat*
 - Fix race due to updates of shared a map, that was not supposed to be shared between multiple go-routines. {issue}6616[6616]