prevent setup.py from adding RPATHs

--- cy_build.py
+++ cy_build.py
@@ -81,6 +81,5 @@
             if not ext.extra_link_args:
                 ext.extra_link_args = []
 
-            ext.extra_link_args += ['-Wl,-rpath,$ORIGIN']
                                     
         build_ext.build_extension(self, ext)