The manifest entry for `koreader/frontend/socketutil.lua` is wrong:
```
koreader/frontend/socketutil.lua/
```
That's because the CRC for that file (0E376639) compare as a false value
when used conditionally with `if (0E376639)`. The correct way to check
for an empty string is to use: `if (0E376639 != "")`.
NOTE: no impact that I could see on the actual generated archive, e.g.
for kindlepw2: the file is still included.
Instead of splitting remove / exclusion of unwanted files in 2-3 places
(`all` rule, `update` rule, and update script in some cases), install
the same files in debug & release builds, and exclude unwanted stuff
when generating the update.
This should finally fix the CI issue with OCR tests (since we don't
remove the `data/dict` & `data/tessdata` directories on release build
anymore).
