perl-libwww: remove hash file

As reported by Romain Naour, having a hash file for a package
downloaded from github is wrong.

Reported-by: Romain Naour <romain.naour@openwide.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/perl-libwww/perl-libwww.hash

@@ -1,3 +0,0 @@
-# retrieved by scancpan from http://cpan.metacpan.org/
-md5    85b36bcd2fd2450718ee14f894f0d3d1 libwww-perl-6.13.tar.gz
-sha256 5fbd13eebd1933e5a203fceb2c1629efbccff3efc8fab6ec0285c79d0a95f8b2 libwww-perl-6.13.tar.gz