defaults: remove /usr/lib/gcc* from ldconfig search path

defaults: remove /usr/lib/gcc* from ldconfig search path

It is not necessary for ldconfig to add /usr/lib/gcc44 and /usr/lib/gcc41
directories to the default library search path.  Every binary built with
gcc41 and gcc44 embeds these paths into the DT_RPATH dynamic tag which
tells the runtime linker to look their first.  In effect, this means these
paths are potentially searched multiple times: once due to the rpath and
again due to the ldconfig hints file.  Let's do away will the redundant,
always-fails check here.

Another reason is that the gcc libraries have different versions of the
same libraries.  Surely the gcc41 version isn't preferred over the gcc44
version, but it gets searched first.  Again, let rpath take care of this
for gcc.

To update the rc.conf defaults, "make upgrade" after building world is
required.