Commit 8c8e5d52 added a way to reduce
seek time by waiting for the windowed tcp packets instead of creating a
new socket connection. It implemented this by overwriting
s->short_seek_threshold in avio_seek(). However,
s->short_seek_threshold could already be set and be higher than the
threshold set by the protocol (i.e. s->short_seek_threshold is set in
ff_configure_buffers_for_index()).

This new feature was only enabled for tls connections in
70d8077b. As in Ticket #9148 it reduced
performance because instead of waiting to refill the AVIOContext buffers
with an existing connections, a new HTTP request was often made instead.

Fixes Ticket #9148.
Reviewed-by: Martin Storsjö <martin@martin.st>
Signed-off-by: Andriy Gelman <andriy.gelman@gmail.com>