handle error when user searches for a lieu that doesn't have associated motifs

Created by: adipasquale

https://trello.com/c/P07xCD4Q/1081-corriger-bug-pendant-recherche-usager-quand-un-motif-a-disparu-pour-le-lieu-courant

https://sentry.io/organizations/rdv-solidarites/issues/1756911462/?environment=production&project=1811205&query=is%3Aunresolved

testable sur la review app via ce lien : https://demo-rdv-solidarites-pr878.osc-fr1.scalingo.io/lieux/5?date=2020-09-14+11%3A00%3A00+%2B0200&search%5Bcity_code%5D=75056&search%5Bdepartement%5D=75&search%5Blatitude%5D=48.845&search%5Blongitude%5D=2.3752&search%5Bmotif_name%5D=Consultation+pr%C3%A9natale&search%5Bservice%5D=1&search%5Bwhere%5D=Paris%2C+75001%2C+75%2C+Paris%2C+%C3%8Ele-de-France

(j'ai accédé a cette recherche puis j'ai supprimé toutes les plages d'ouvertures de l'orga)