Deb: don't edit control file from inside rules file

It's too late. Might work or not (and on buster it doesn't).

debian/autobake-deb.sh

@@ -89,6 +89,11 @@ then
   sed '/Package: mariadb-plugin-aws-key-management-10.2/,+12d' -i debian/control
 fi
 
+# Don't build cassandra package if thrift is not installed
+if [[ ! -f /usr/local/include/thrift/Thrift.h && ! -f /usr/include/thrift/Thrift.h ]]
+then
+  sed '/Package: mariadb-plugin-cassandra/,/^$/d' -i debian/control
+fi
 
 # Adjust changelog, add new version
 echo "Incrementing changelog and starting build scripts"

debian/rules

@@ -120,11 +120,6 @@ ifneq ($(ARCH), amd64)
 	sed -i -e "/Package: mariadb-plugin-tokudb/,+16d" debian/control
 endif
 
-	# If libthrift-dev was available (manually installed, as it is
-	# not in Debian) and ha_cassandra.so was thus built, create package,
-	# otherwise skip it.
-	[ -f $(BUILDDIR)/storage/cassandra/ha_cassandra.so ] || sed -i -e "/Package: mariadb-plugin-cassandra/,+18d" debian/control
-
 	# Copy systemd files to a location available for dh_installinit
 	cp $(BUILDDIR)/support-files/mariadb.service debian/mariadb-server-10.2.mariadb.service
 	cp $(BUILDDIR)/support-files/mariadb@.service debian/mariadb-server-10.2.mariadb@.service