[Integrated] RFR: Add tags to subjects instead of replacing them

[duke]

Changeset: 2b9e3d54
Author:    Robin Westberg <rwestberg at openjdk.org>
Date:      2019-09-16 13:42:31 +0000
URL:       https://git.openjdk.java.net/skara/commit/2b9e3d54

Add tags to subjects instead of replacing them

Reviewed-by: ehelin

! bots/mlbridge/src/main/java/org/openjdk/skara/bots/mlbridge/ReviewArchive.java
! bots/mlbridge/src/test/java/org/openjdk/skara/bots/mlbridge/MailingListBridgeBotTests.java