SIP-27: Re-word that the impl PR == the current proposal

Author: dwijnand

sips/completed/_posts/2016-06-25-trailing-commas.md

@@ -193,7 +193,7 @@ class Bippy(
 
 ## Implementation
 
-The implementation of trailing commas is a matter of changing some of the implementation of Scala's parser. An implementation of an earlier version of this proposal can be found at [scala/scala#5245][].
+The implementation of trailing commas is a matter of changing some of the implementation of Scala's parser. An implementation of this proposal can be found at [scala/scala#5245][].
 
 ## Drawbacks/Trade-offs