Revert "httpendpoint: Fix race condition when reconfiguring internal pipeline"

This reverts commit bee6d5737ede2ea373027e065b533f1119cf434d.
This commit is causing a segmentation fault when used in the mediaserver.

Reverted commit review:
https://repository.kurento.com/gerrit/5009/

Change-Id: I7fa56f0063580e719082542bad7ecc931b60ee40