Do not require SiteConfig.tagline (#10623) [deploy]

* Fix incorrect formatting in admin/configs/show.html.erb

* Only render SiteConfig.tagline if it exists

* Fix typo in _signup_modal.html.erb

* Remove tagline from VerifySetupCompleted::MANDATORY_CONFIGS

* Improve signup_modal tagline specs

* Tiny fixes to address @citizen428's comments

app/controllers/concerns/verify_setup_completed.rb

@@ -7,7 +7,6 @@ module VerifySetupCompleted
     community_name
     community_description
     community_action
-    tagline
 
     main_social_image
     logo_png

app/views/devise/invitations/edit.html.erb

@@ -2,7 +2,9 @@
 <div class="crayons-layout crayons-layout--limited mb-10" style="max-width:640px">
   <div class="crayons-notice mt-4">
     <h1>Welcome to <%= community_name %></h1>
-    <h3><%= SiteConfig.tagline %></h3>
+    <% if SiteConfig.tagline.present? %>
+      <h3><%= SiteConfig.tagline %></h3>
+    <% end %>
   </div>
   <div class="mt-3 crayons-card p-7 align-left">
     <h2>Set a password to access your account</h2>

app/views/layouts/_signup_modal.html.erb

@@ -19,7 +19,7 @@
             <% if SiteConfig.tagline.present? %>
               <%= SiteConfig.tagline %>
             <% else %>
-              We’d love for you to be apart of this community.
+              We’d love for you to be a part of this community.
             <% end %>
           </p>
         </div>

spec/views/layouts/signup_modal.html.erb_spec.rb

@@ -1,8 +1,17 @@
 require "rails_helper"
 
 RSpec.describe "layouts/_signup_modal.html.erb", type: :view do
-  it "has the tagline" do
+  let(:tagline_text) { "the best community" }
+
+  it "renders the tagline if it is set" do
+    allow(SiteConfig).to receive(:tagline).and_return(tagline_text)
     render
     expect(rendered).to have_text(SiteConfig.tagline)
   end
+
+  it "does not render the tagline if it is not set" do
+    allow(SiteConfig).to receive(:tagline).and_return(nil)
+    render
+    expect(rendered).not_to have_text(tagline_text)
+  end
 end