Dependency renamed on Debian 10

[aderbenev]

Just preserving a note here that x11proto-print-dev has changed to x11proto-dev since the former is not available since at least Buster (Deb10). Adjusting the dependency results in a successful build.

[chrschroeder]

I removed this dependency since it doesn't seem to be used at all. libXp was also removed on upstream (gnartohl/edm@6c2594c). The change is included in my last pull request which I merged just now after almost a year of usage on Debian 11.