process_fts_updates: Support arbitrary database user and dbname.
process_fts_updates: Support arbitrary database user and dbname.

Co-authored-by: Adam Birds <a4b17ee8ffd707e7fe6b66c3737fdd8fbd524cdd@adbwebdesigns.co.uk>

andersk/zulip,eeshangarg/zulip,andersk/zulip,eeshangarg/zulip,kou/zulip,zulip/zulip,eeshangarg/zulip,eeshangarg/zulip,rht/zulip,kou/zulip,zulip/zulip,punchagan/zulip,rht/zulip,hackerkid/zulip,punchagan/zulip,hackerkid/zulip,eeshangarg/zulip,andersk/zulip,zulip/zulip,zulip/zulip,andersk/zulip,zulip/zulip,hackerkid/zulip,punchagan/zulip,kou/zulip,andersk/zulip,rht/zulip,kou/zulip,andersk/zulip,rht/zulip,rht/zulip,eeshangarg/zulip,punchagan/zulip,eeshangarg/zulip,kou/zulip,punchagan/zulip,kou/zulip,hackerkid/zulip,rht/zulip,zulip/zulip,andersk/zulip,kou/zulip,hackerkid/zulip,zulip/zulip,punchagan/zulip,hackerkid/zulip,punchagan/zulip,rht/zulip,hackerkid/zulip