Everyone has the right to freedom of thought, conscience and religion; this right includes freedom to change his religion or belief, and freedom, alone or in community with others, and, in public or private, to manifest his religion or belief in teaching, practice, worship and observance.
Nothing I can see there about any right to religious erections! However, as I understand Islam one of its precepts is that once in that religion you do not have the right to change your belief, on pain of death. This is known as apostasy. This is surely a greater violation of article 18. Also there is the fact that some Muslim countries do not permit the building of Christian churches at all, so the Swiss ban is piffling in contrast.
Here is a related article from The Freethinker. The video by Dr Zakir Naik explains why, Christianity just doesn't add up!