[SeaMonkey] late-l10n implications on comm-beta by Bug 1446199

[RSX11M]

https://bugzilla.mozilla.org/show_bug.cgi?id=1446199 moved the
image-animation settings from Privacy & Security > Images to
Appearance > Media, this part also landed on comm-beta

https://hg.mozilla.org/releases/comm-beta/rev/31fae9500e16

Note that no strings were moved (comm-central only). The
pref-images.dtd strings are used in pref-media.xul for comm-beta,
however there may be an accesskey conflict now with the
allowMediaAutoplay checkbox introduced in
https://bugzilla.mozilla.org/show_bug.cgi?id=493217

There have also been related Help updates pushed to comm-beta, in case
you are translating those (not essential to build SeaMonkey as such).
We hop to get the Help Viewer running again by the time the first 2.57
is released.

https://hg.mozilla.org/releases/comm-beta/rev/7dc0273dfea0

Sorry for any inconvenience, but we'd like to take this for 2.57 on
the upcoming new ESR branch.