Update notes for submitted changes

* app_mp3: remove 10 seconds of silence after mp3 playback

b5/1c4a04385311875c1f9e0820907468c4b82c0b

@@ -0,0 +1,9 @@
+Code-Review+1: Benjamin Keith Ford <bford@digium.com>
+Code-Review+1: Richard Mudgett <rmudgett@digium.com>
+Code-Review+2: Joshua Colp <jcolp@digium.com>
+Verified+2: Joshua Colp <jcolp@digium.com>
+Submitted-by: Joshua Colp <jcolp@digium.com>
+Submitted-at: Mon, 18 Jun 2018 07:39:07 -0500
+Reviewed-on: https://gerrit.asterisk.org/9189
+Project: asterisk
+Branch: refs/heads/15