Fix LD_LIBRARY_PATH for NetBSD.

LibreOffice 4 NetBSD build fails with wrong LD_LIBRARY_PATH.
LD_LIBRARY_PATH setting in solenv/gbuild/platform/NETBSD_INTEL_GCC.mk and
solenv/gbuild/platform/NETBSD_X86_64_GCC.mk is not needed.
Attached patch should fix amd64 (x86_64) and i386 build.

https://bugs.freedesktop.org/show_bug.cgi?id=77098

Signed-off-by: Thomas Klausner <wiz@NetBSD.org>