Ignore build dependencies on the host system

When we are building the binary packages inside an schroot, they will be
fetched and installed. We don't need them on the host running sbuild.

package-deb

@@ -70,7 +70,7 @@ cd "$DIST_DIR"
 dch -v "$FULL_VERSION" "$DCH_TEXT"
 
 # Generate the source package used by subsequent sbuilds
-dpkg-buildpackage -us -uc -S -j10
+dpkg-buildpackage -us -uc -S -j10 -d
 
 # Back to build/
 cd ..