BUG #17979: (pg_tsparser + ts_headline) duplicate output if dot present

The following bug has been logged on the website:

Bug reference:      17979
Logged by:          Artem
Email address:      vicreal@yandex.ru
PostgreSQL version: 14.4
Operating system:   Windows 10
Description:

CREATE EXTENSION pg_tsparser;
CREATE TEXT SEARCH CONFIGURATION public.vp_ts_config_test (PARSER =
tsparser);
SELECT ts_headline('vp_ts_config_test', 'one.two',
websearch_to_tsquery('three'), 'HighlightAll=TRUE, StartSel="<mark>",
StopSel="</mark>"');

Result:
one.twoone.two

Must be:
one.two