Before refactoring nmcli recently, field names were marked for translation.
Note that for the property names, marking them had no effect as only
plain strings can be marked with N_().

Note how --fields are also an input argument. The input should be
independent of the locale and not translated. Likewise, when printing
the header names, they should not be translated to match the --fields
option.

    $ LANG=de_DE.utf8 nmcli --fields GENERAL.DEVICE device show enp0s25
    GENERAL.GERÄT:                          enp0s25

Drop the translation marks.