Drop the mysqld multi patches as they are no longer relevant

The author Jan Wagner confirmed the patches can be dropped as they are no
longer relevant with systemd. From now on the correct approach would be
to follow the method described in the MariaDB knowledgebase:
https://mariadb.com/kb/en/library/systemd/#interacting-with-multiple-mariadb-server-processes

debian/patches/mysqld_multi.server_lsb-header.patch

-From: Debian MySQL Maintainers <pkg-mysql-maint@lists.alioth.debian.org>
-Date: Thu, 10 Aug 2017 20:40:28 +0200
-Subject: mysqld_multi.server_lsb-header
-
----
- support-files/mysqld_multi.server.sh | 20 ++++++++++++++++++--
- 1 file changed, 18 insertions(+), 2 deletions(-)
-
---- a/support-files/mysqld_multi.server.sh
-+++ b/support-files/mysqld_multi.server.sh
-@@ -14,8 +14,24 @@
- # Version 1.0
- #
- 
--basedir=/usr/local/mysql
--bindir=/usr/local/mysql/bin
-+### BEGIN INIT INFO
-+# Provides:          mysqld_multi
-+# Required-Start:    $remote_fs $syslog
-+# Required-Stop:     $remote_fs $syslog
-+# Should-Start:      $network $named $time
-+# Should-Stop:       $network $named $time
-+# Default-Start:     2 3 4 5
-+# Default-Stop:      0 1 6
-+# Short-Description: Start and stop multiple mysql database server daemon instances
-+# Description:       Controls multiple MariaDB database server daemon instances
-+### END INIT INFO
-+
-+PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
-+NAME=mysqld_multi
-+DESC=mysqld_multi
-+
-+basedir=/usr
-+bindir=/usr/bin
- 
- if test -x $bindir/mysqld_multi
- then

debian/patches/mysqld_multi_confd.patch

-From: Debian MySQL Maintainers <pkg-mysql-maint@lists.alioth.debian.org>
-Date: Thu, 10 Aug 2017 20:40:28 +0200
-Subject: mysqld_multi_confd
-
----
- scripts/mysqld_multi.sh | 1 +
- 1 file changed, 1 insertion(+)
-
---- a/scripts/mysqld_multi.sh
-+++ b/scripts/mysqld_multi.sh
-@@ -497,6 +497,7 @@ sub list_defaults_files
-                '@prefix@/my.cnf',
-                ($ENV{MYSQL_HOME} ? "$ENV{MYSQL_HOME}/my.cnf" : undef),
-                $opt{'extra-file'},
-+               </etc/mysql/conf.d/*.cnf>,
-                ($ENV{HOME} ? "$ENV{HOME}/.my.cnf" : undef));
- }
- 

debian/patches/series

 disable-test-disks.patch
 extend_default_test_timeout_for_tokudb.patch
 innodb_simulate_comp_test_speedup.patch
-#mysqld_multi_confd.patch
-#mysqld_multi.server_lsb-header.patch
 mips-groonga-atomic.patch
 mips-connect-unaligned.patch
 mips-machine.patch