updated a link for P0. Persistent Java compiler is enabled

--
Change-Id: I699d605b3dc923a60516d70dc5d0144a9be49b0b
Reviewed-on: https://bazel-review.googlesource.com/#/c/6310/1
MOS_MIGRATED_REVID=134466041
diff --git a/site/roadmap.md b/site/roadmap.md
index 94c4aa1..3b1f39d 100644
--- a/site/roadmap.md
+++ b/site/roadmap.md
@@ -116,7 +116,8 @@
     <tr>
       <td rowspan="2"><b>0.4</b></td>
       <td rowspan="2"><b>2016&#8209;10</b></td>
-      <td>P0. Persistent Java compiler is enabled</td>
+      <td>P0.<a
+      href="https://github.com/bazelbuild/bazel/commit/490f250b27183a886cf70a5fe9e99d9428141b34"> Persistent Java compiler is enabled</a></td>
     </tr>
     <tr><td>P2. Sandboxing of action for OS X</td></tr>
     <tr>