ability to use middle mouse button to close tabs - #60

The portability commit changed two msgids -- the two "Terminating /
Killing amuleweb instance with pid '%d' ... " log messages -- from
`%ld` to `%d` to match the new `int` type of `webserver_pid`.
CFormat is type-safe so the rendered output is unchanged, but the
extracted msgids drift so the .pot and every .po has to be regenerated.

msgmerge marked the two updated entries `#, fuzzy` in each catalog
that previously translated them. The only difference between the old
and new msgstr is the same %ld -> %d swap, so this is a mechanical
fix: each affected msgstr has its `%ld` replaced with `%d` and the
fuzzy marker dropped. No human translation work needed -- all
languages keep their existing wording.

Catalogs that already had the entries untranslated, and unrelated
pre-existing fuzzy entries (e.g. the English (U.S.) marker from
PR amule-project#60), are left untouched.