remove dead link (#271)

docs/introduction.rst

@@ -14,7 +14,7 @@ The rocSHMEM programming model
 -------------------------------
 
 Defining how OpenSHMEM applications interact with GPUs remains an
-ongoing active discussion within the `OpenSHMEM <http://www.openshmem.org/site/>`_ community, and the OpenSHMEM
+ongoing active discussion within the OpenSHMEM community, and the OpenSHMEM
 specification has yet to coalesce on this topic.
 rocSHMEM extends beyond the OpenSHMEM specification to add semantics that
 support GPU kernel communication while maintaining close resemblance to