update nsfwCensorImage suggestion in config/description.exs

Turns out this is also used to set the default values in adminfe, so
update this to the correct URL for the NSFW banner so that it doesn't
break if you reset this value.

config/description.exs

@@ -1184,7 +1184,7 @@
             logoMask: true,
             minimalScopesMode: false,
             noAttachmentLinks: false,
-            nsfwCensorImage: "/static/img/nsfw.74818f9.png",
+            nsfwCensorImage: "/static/img/nsfw.b81b2e9.png",
             postContentType: "text/plain",
             redirectRootLogin: "/main/friends",
             redirectRootNoLogin: "/main/all",
@@ -1285,7 +1285,7 @@
             type: {:string, :image},
             description:
               "URL of the image to use for hiding NSFW media attachments in the timeline",
-            suggestions: ["/static/img/nsfw.74818f9.png"]
+            suggestions: ["/static/img/nsfw.b81b2e9.png"]
           },
           %{
             key: :postContentType,