Moved update of DNA plugin among update plugins
To make the code more general, moved the update_dna_shared_config
among other update plugins.
Bugfix: DNA shared config connection protocol was compared to a
method string which would result in a try to always update it
even if there was no need to.
https://fedorahosted.org/389/ticket/48373 causes that two
shared DNA config entries are created instead of one.
Reviewed-By: Martin Babinsky <firstname.lastname@example.org>
Reviewed-By: Jan Cholasta <email@example.com>