Deb: Remove dependencies on packages that are 'essential' anyway

All packages in group 'essential' are by default installed on all
Debian and Ubuntu systems, and there is no need to mark them as
dependencies for any binary.

debian/control

@@ -421,10 +421,7 @@ Recommends: libhtml-template-perl
 Pre-Depends: adduser (>= 3.40),
              debconf,
              mariadb-common (>= ${source:Version})
-Depends: bsdutils,
-         coreutils,
-         findutils,
-         galera-3 (>=25.3),
+Depends: galera-3 (>=25.3),
          gawk,
          iproute2,
          libdbi-perl,