[Xfce-i18n] Fill out po headers (Project-Id-Version)

[scootergrisen]

When i check translation po files i like to run stuff likfe msgfmt -cv 
to see it the files are ok.

But some of the Xfce po files have:

#, fuzzy
msgid ""
msgstr ""
"Project-Id-Version: PACKAGE VERSION\n"

Which makes msgfmt say:
msgfmt: ./xfce-apps.catfish/da.po: warning: PO file header fuzzy
                                    warning: older versions of msgfmt 
will give an error on this
./xfce-apps.catfish/da.po:12: warning: header field 'Project-Id-Version' 
still has the initial default value

So i would like it to be filled out the all the po files in the future.