Revert r1728874:

Revert r1728874:
Netware: pull up ws2nlm imports from all (most)
proxy module makefiles to the main proxy makefile.

The individual module Makefiles overwrite
FILES_nlm_Ximports instead of appending.
Furthermore, now we know which modules need
this import so we can set it specifically
for those.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1729290 13f79535-47bb-0310-9956-ffa450edef68