Impossible to see the public profile of a user who has a "." in its nickname

So far it's possible to choose a nickname that has a "." in it (for instance, "julie.simon"). Since the profile's url is https://meta.decidim.org/profiles/[nickname]/, when trying to load https://meta.decidim.org/profiles/julie.simon, we get a server error. Maybe there should be a validation which makes it impossible to have a "." in its nickname