Small ReST syntax fix.

NEWS.txt

@@ -56,8 +56,8 @@ Optimizations:
    * Removed scan double compilation (by using the new Op.make_thunk mechanism)
    * Certain computations from the inner graph are now Pushed out into the outer
      graph. This means they are not re-comptued at every step of scan.
-   * Different scan ops get merged now into a single op (if possible), reducing the
-   overhead and sharing computations between the two instances
+   * Different scan ops get merged now into a single op (if possible), reducing
+     the overhead and sharing computations between the two instances
 
 GPU: