Fix the mod_dav_svn Windows build.
Fix the mod_dav_svn Windows build.

* subversion/mod_dav_svn/mod_dav_svn.dsp: Removed libsvn_subr/pipe.c.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion