Ensure that current_person exists before checking the policy

Author: rsmithlal

app/views/layouts/better_together/_mobile_bar.html.erb

@@ -1,6 +1,6 @@
 <div id="mobile-bar" class="container-fluid shadow-sm d-lg-none">
   <nav class="d-flex justify-content-around align-items-center py-4" aria-label='<%= t('better_together.mobile_bar.navigation') %>'>
-    <% if policy(current_person).show? %>
+    <% if current_person && policy(current_person).show? %>
       <%= link_to person_my_profile_path(person_id: current_person.slug), class: "text-light", aria: { label: t('better_together.mobile_bar.profile') }, data: { bs_toggle: "tooltip", bs_placement: "top", bs_title: t('better_together.mobile_bar.profile') } do %>
         <i class="fas fa-user fa-2x" aria-hidden="true"></i>
         <span class="visually-hidden"><%= t('better_together.mobile_bar.profile') %></span>