Do not send an email on reviewes when there is no message.

No longer send an email when reviewing a change via ssh, and
the change message is blank (when no change message is actually
added to the review).  This occured when an approval was
repeated (no change), and no message was explicitly added.

Issue: 1069
Change-Id: Ibf6cd970fdb81ffc1353a2675a2f21a23c46a2cd
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/patch/PublishComments.java b/gerrit-server/src/main/java/com/google/gerrit/server/patch/PublishComments.java
index 8efb4ae..1d43453 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/patch/PublishComments.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/patch/PublishComments.java
@@ -285,12 +285,14 @@
 
   private void email() {
     try {
-      final CommentSender cm = commentSenderFactory.create(change);
-      cm.setFrom(user.getAccountId());
-      cm.setPatchSet(patchSet, patchSetInfoFactory.get(patchSetId));
-      cm.setChangeMessage(message);
-      cm.setPatchLineComments(drafts);
-      cm.send();
+      if (message != null) {
+        final CommentSender cm = commentSenderFactory.create(change);
+        cm.setFrom(user.getAccountId());
+        cm.setPatchSet(patchSet, patchSetInfoFactory.get(patchSetId));
+        cm.setChangeMessage(message);
+        cm.setPatchLineComments(drafts);
+        cm.send();
+      }
     } catch (EmailException e) {
       log.error("Cannot send comments by email for patch set " + patchSetId, e);
     } catch (PatchSetInfoNotAvailableException e) {