bug#20779: 25.0.50; executable-self-display adds wrong magic line

[Nicolas Richard]

The command executable-self-display adds:
    #!/usr/bin/tail +2
as the first line.

This doesn't work with my version of tail:

$ tail --version
tail (GNU coreutils) 8.21

I get:
$ LANG=C /tmp/test
/usr/bin/tail: cannot open '+2' for reading: No such file or directory
==> /tmp/test <==
#!/usr/bin/tail +2
foo bar

For it to work, it would need to be 
    #!/usr/bin/tail -n+2

I have no suggestion to fix this (Is it even worth fixing ?)

Nico.