[packaging] Fix postun scriptlet error

Removing the comment under the %postun macro will get rid of
errors like these when upgrading the package:

"/sbin/ldconfig: relative path '1' used to build cache"

Explanation can be found here:

http://en.opensuse.org/openSUSE:Packaging_scriptlet_snippets

Signed-off-by: Juha Kallioinen <juha.kallioinen@jollamobile.com>