autobake-deb: Stop packaging plugins that are not built

This complements commit ecb0e0ade4 that
disabled a bunch of plugins from being built on Travis-CI (due to time
and disk space saving reasons).

When the plugins are not built, the packaging phase will fail due to
missing files. This change omits the files from packaging to the process
can complete successfully.

debian/autobake-deb.sh

@@ -136,6 +136,9 @@ if [[ $TRAVIS ]]
 then
   sed -i -e "/Package: mariadb-plugin-tokudb/,+17d" debian/control
   sed -i -e "/Package: mariadb-plugin-mroonga/,+16d" debian/control
+  sed -i -e "/Package: mariadb-plugin-spider/,+18d" debian/control
+  sed -i -e "/Package: mariadb-plugin-oqgraph/,+16d" debian/control
+  sed -i -e "/usr\/lib\/mysql\/plugin\/ha_sphinx.so/d" debian/mariadb-server-10.3.install
 fi
 
 # Adjust changelog, add new version