If an httpd body writer is called with output_stream<>, it mist close the stream on its own regardless of any exceptions it may generate while working, otherwise stream destructor may step on non-closed assertion. Stepped on with different handler, see #19541
Coroutinize the handler as the first step while at it (though the fix would have been notably shorter if done with .finally() lambda)
Closesscylladb/scylladb#19543
* github.com:scylladb/scylladb:
api: Close response stream of get_compaction_history()
api: Flush output stream in get_compaction_history() call
api: Coroutinize get_compaction_history inner function