[ticket/11368] Fix background color for PM report rows by using accessing var.

PHPBB3-11368
[ticket/6723] Show info that message has been deleted before delivery

If the message has been deleted before the delivery it will still show in
the message history, although with an empty message. This patch will
change that behavior to showing the info that it has been deleted before
it was delivered in red letters. The red letters ensure that users won't
mistake the info for the actual message.

PHPBB3-6723
Merge remote-tracking branch 'remotes/bantu/ticket/11368' into develop-olympus

# By Andreas Fischer
# Via Andreas Fischer
* remotes/bantu/ticket/11368:
  [ticket/11368] Fix background color for PM report rows by using accessing var.
Merge remote-tracking branch 'remotes/upstream/develop-olympus' into develop

# By Andreas Fischer
# Via Andreas Fischer (1) and Nathaniel Guse (1)
* remotes/upstream/develop-olympus:
  [ticket/11368] Fix background color for PM report rows by using accessing var.
Merge remote-tracking branch 'remotes/marc/ticket/6723' into develop-olympus

# By Marc Alexander
# Via Marc Alexander
* remotes/marc/ticket/6723:
  [ticket/6723] Show info that message has been deleted before delivery
Merge remote-tracking branch 'remotes/upstream/develop-olympus' into develop

# By Marc Alexander
# Via Marc Alexander (1) and Nathaniel Guse (1)
* remotes/upstream/develop-olympus:
  [ticket/6723] Show info that message has been deleted before delivery
Merge branch 'develop' into feature/revisions

# By Andreas Fischer (1) and Marc Alexander (1)
# Via Nathaniel Guse (4) and Marc Alexander (1)
* develop:
  [ticket/6723] Show info that message has been deleted before delivery
  [ticket/11368] Fix background color for PM report rows by using accessing var.