Revert r1533530.  It turns out that APR_TCP_NODELAY will have no effect
on real ethernet connections but only the loopback (localhost) device.
Tested with 'svn-bench null-list' over 1GbE and 10GbE on Linux.

git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1539207 13f79535-47bb-0310-9956-ffa450edef68