Fix incorrect printers.target in CUPS systemd unit installation

[Douglas R. Reno]

Following the instructions in the book will result in the following output:

renodr [ /sources/cups-2.4.0 ]$ sudo systemctl enable cups
Created symlink /etc/systemd/system/printers.target.wants/cups.service → /usr/lib/systemd/system/cups.service.
Unit /usr/lib/systemd/system/cups.service is added as a dependency to a non-existent unit printers.target.
Created symlink /etc/systemd/system/multi-user.target.wants/cups.service → /usr/lib/systemd/system/cups.service.
Created symlink /etc/systemd/system/sockets.target.wants/cups.socket → /usr/lib/systemd/system/cups.socket.
Created symlink /etc/systemd/system/multi-user.target.wants/cups.path → /usr/lib/systemd/system/cups.path.

A pull request upstream has fixed this bug: ​https://github.com/OpenPrinting/cups/pull/316

While it is a harmless message, for consistency, it should be put in 'printer.target' instead of the non-existent 'printers.target'.

[Douglas R. Reno]

I'm going to try the following sed to fix this:

sed -e "s/printers.target/printer.target/" -i configure -i config-scripts/cups-defaults.m4

EDIT: Fixed sed

[Douglas R. Reno]

That sed works and places cups.service into the right target. I'll drop this in with gexiv2 and adwaita-icon-theme shortly.

[Douglas R. Reno]

Fixed at 284dd89d01d07e664d04520737f56f3d31899eb0