Do not automatically add reviewers from footer lines to drafts

Gerrit already avoids adding the author/committer as reviewer to
the draft.  However, it would still add those reviewers found in
the footer lines of the commit message and would notify those from
'CC' footer lines about the draft. I think this wasn't intended.

Change-Id: Ic62b5dc47fafb01d5d23148009a333bf09b863c4
Signed-off-by: Sasa Zivkov <sasa.zivkov@sap.com>

gerrit-server/src/main/java/com/google/gerrit/server/git/ReceiveCommits.java

@@ -1318,6 +1318,9 @@ public class ReceiveCommits {
       final List<FooterLine> footerLines = commit.getFooterLines();
       for (final FooterLine footerLine : footerLines) {
         try {
+          if (ps.isDraft()) {
+            continue;
+          }
           if (isReviewer(footerLine)) {
             reviewers.add(toAccountId(footerLine.getValue().trim()));
           } else if (footerLine.matches(FooterKey.CC)) {