[DL] String additions to 'gnome-software.master'

[GNOME Status Pages <noreply gnome org>]

This is an automatic notification from status generation scripts on:
https://l10n.gnome.org.

There have been following string additions to module 'gnome-software.master':

+ "Unable to purchase %s"
    + "Unable to purchase %s: authentication was invalid"
    + "Unable to purchase %s: authentication was required"
    + "Unable to purchase %s: no payment method setup"
    + "Unable to purchase %s: payment was declined"

Note that this doesn't directly indicate a string freeze break, but it
might be worth investigating.
https://git.gnome.org/browse/gnome-software/log/?h=master