SCRIPTS: announce-release: place the send command in the mail's header

I'm fed up with having to scroll my terminals trying to look for the
mail send command printed 30 minutes before the release, let's have
it copied into the e-mail template itself, and replace the old headers
that used to be duplicated there and that are not needed anymore.

(cherry picked from commit 0f5ce6014acc7e6cbdcde110f950d367bb19b75b)
Signed-off-by: Willy Tarreau <w@1wt.eu>
(cherry picked from commit 119d44bc34c995845e1f15782af3c15c2993b5d4)
Signed-off-by: Willy Tarreau <w@1wt.eu>
diff --git a/scripts/announce-release b/scripts/announce-release
index 972d6ea..62e7986 100755
--- a/scripts/announce-release
+++ b/scripts/announce-release
@@ -117,9 +117,12 @@
 	die "$HTML already exists, please remove it."
 fi
 
-(echo "Subject: [ANNOUNCE] haproxy-$NEW"
- echo "To: haproxy@formilux.org"
- echo
+(
+ echo "# Send this using:"
+ echo "#   mutt -i <(tail -n +4 ${OUTPUT##*/}) -s \"[ANNOUNCE] haproxy-$NEW\" haproxy@formilux.org"
+) >> "$OUTPUT"
+
+(echo
  echo "Hi,"
  echo
  echo -n "HAProxy $NEW was released on $DATE. It added "
@@ -210,7 +213,7 @@
 echo "The announce was emitted into file $OUTPUT."
 echo "You can edit it and send it this way :"
 echo
-echo "   mutt -i ${OUTPUT##*/} -s \"[ANNOUNCE] haproxy-$NEW\" haproxy@formilux.org"
+echo "   mutt -i <(tail -n +4 ${OUTPUT##*/}) -s \"[ANNOUNCE] haproxy-$NEW\" haproxy@formilux.org"
 echo
 echo "The HTML block was emitted into $HTML and needs to be finished by hand."
 echo