Quoting J. Fahrner: "Why do you think I have 45 languages installed?
You do not need to install thunderbird-l10n-all, there is a single
package for every language. For example thunderbird-l10n-de."

If that is the case, then, there is no need of hacks.

--
If you can't explain it simply, you don't understand it well enough.
(Albert Einstein)
If you cannot make abstructions about details you do not understand
the concepts underlying them.