Make it so that if there is no custom mascot uploaded the logo on the about/more page will always be correctly coloured

app/javascript/styles/mastodon/about.scss

@@ -846,6 +846,12 @@ h1 a.brand {
   font-size: 3.8em;
 }
 
+.originalmascotimg svg {
+  width: 200px;
+  fill: $secondary-text-color;
+  margin-top: -25px;
+}
+
 .brand__tagline {
   display: block;
   position: absolute;

app/views/about/more.html.haml

@@ -24,8 +24,13 @@
             %strong= number_with_delimiter @instance_presenter.status_count
             %span= t 'about.status_count_after', count: @instance_presenter.status_count
         .row__mascot
-          .landing-page__mascot
-            = image_tag @instance_presenter.mascot&.file&.url || asset_pack_path('media/images/elephant_ui_plane.svg'), alt: ''
+          - if @instance_presenter.mascot&.file&.url
+            .landing-page__mascot
+              = image_tag @instance_presenter.mascot&.file&.url
+          - else
+            .landing-page__mascot{:class => ("originalmascot")}
+              %div{:class => ("originalmascotimg")}
+                = svg_logo
 
   .column-2
     .landing-page__information.contact-widget