OpenResty: remove `LDFLAGS` unknown `-R` option

GCC 4.6+ rejects unknown options, previously passed to the linker. Fix 
is to remove the `-R` option which is not needed here.

This patch will enable:

* Updating OSC to use OpenResty for it's load balance dep.
* Building OPC on Ubuntu 12.04 LTS.

This fix has been fully tested with the OSC pipeline:
http://andra.ci.opscode.us/job/chef-server-trigger-ad-hoc/63/downstreambuildview/?

/cc @lamont-granquist @hosh @christophermaier @seth