Remove scala-opt link

Author: OlivierBlanvillain

_posts/2015-05-05-release-notes-2.12.0-M1.md

@@ -38,7 +38,7 @@ The following changes are planned for Scala 2.12:
 * New backend and optimizer.
   The "GenBCode" backend, which is already available in Scala 2.11 using the `-Ybackend:GenBCode` compiler option, will be enabled by default.
   Scala 2.12 will also ship with a new inliner and bytecode optimizer.
-  We keep track of issues and work items for the new optimizer on the [scala-opt repository issue tracker](https://github.com/scala-opt/scala/issues).
+  We keep track of issues and work items for the new optimizer on the scala-opt repository issue tracker.
 
 The above list is incomplete and will be extended during the Scala 2.12 milestone cycle.
 

_posts/2015-07-14-release-notes-2.12.0-M2.md

@@ -74,7 +74,7 @@ As of M2, the following optimizations are available:
 * If a closure is allocated and invoked within the same method, the closure invocation is replaced by an invocations of the corresponding lambda body method
 * Dead code elimination and a small number of cleanup optimizations
 
-The work on the new optimizer is still ongoing.  You can track it in the [scala-opt repository issue tracker](https://github.com/scala-opt/scala/issues).
+The work on the new optimizer is still ongoing.  You can track it in the scala-opt repository issue tracker.
 
 ### Unbundled features