Bugfix: Typo in 4501c7e that made mariadb-client-core conflict itself

This fixes the apt error:
  The following packages have unmet dependencies:
  mariadb-client-core-10.6 : Conflicts: mariadb-client-10.6 but
  1:10.6.0+maria~sid is to be installed

Author: ottok

debian/control

@@ -252,7 +252,7 @@ Conflicts: mariadb-client-10.0,
            mariadb-client-10.2,
            mariadb-client-10.3,
            mariadb-client-10.4,
-           mariadb-client-10.6,
+           mariadb-client-10.5,
            mariadb-client-10.6 (<< ${source:Version}),
            mariadb-client-5.1,
            mariadb-client-5.2,