audio/abcde: Update from 2.7.2 to 2.8.1

Changelog: https://git.einval.com/cgi-bin/gitweb.cgi?p=abcde.git;a=blob;f=changelog;h=42fc10fd36166d7703fe75e5a5f945f164e5354b;hb=a226ffafbb43cd32d91058bb336e86401418b4a9