perl-mojolicious: bump to version 5.08

- switch to BackPan in order to prevent build breakage
(like http://autobuild.buildroot.net/results/358/358f531f2db90b9bc3b1e4e2158c68d2bf6587fc/)
- add license file

Signed-off-by: Francois Perrad <francois.perrad@gadz.org>