MDEV-519: mariadb-client-5.5 conflicts with package mytop

Do not include mytop in mariadb-client-5.5 .deb package.

There is already a Debian mytop package, so we get a package conflict.
And there is no reason for the MariaDB project to guerrilla-take-over
mytop maintenance.

debian/mariadb-client-5.5.files

@@ -11,7 +11,6 @@ usr/bin/mysqlimport
 usr/bin/mysqlreport
 usr/bin/mysqlshow
 usr/bin/mysqlslap
-usr/bin/mytop
 usr/bin/mysql_waitpid
 usr/share/lintian/overrides/mariadb-client-5.5
 usr/share/man/man1/innotop.1