Add a dot to end of sentence.

services/web/app/views/project/invite/not-valid.jade

@@ -11,7 +11,7 @@ block content
 						.row.text-center
 							.col-md-12
 								p
-									| #{translate("invite_not_valid_description")}
+									| #{translate("invite_not_valid_description")}.
 						.row.text-center.actions
 							.col-md-12
 								a.btn.btn-info(href="/project") #{translate("back_to_your_projects")}