posts: change safe mode to only allow rating:g posts.

app/logical/post_query.rb

@@ -198,7 +198,7 @@ class PostQuery
     return [] unless safe_mode?
 
     tags = Danbooru.config.safe_mode_restricted_tags.map { |tag| -AST.tag(tag) }
-    [AST.metatag("rating", "g,s"), *tags]
+    [AST.metatag("rating", "g"), *tags]
   end
 
   # XXX unify with PostSets::Post#show_deleted?

app/models/post.rb

@@ -1570,7 +1570,7 @@ class Post < ApplicationRecord
   end
 
   def safeblocked?
-    CurrentUser.safe_mode? && (rating.in?(["q", "e"]) || Danbooru.config.safe_mode_restricted_tags.any? { |tag| tag.in?(tag_array) })
+    CurrentUser.safe_mode? && (rating != "g" || Danbooru.config.safe_mode_restricted_tags.any? { |tag| tag.in?(tag_array) })
   end
 
   def levelblocked?(user = CurrentUser.user)