Remove excess share_visibilities from 1/24 HEAD

cleanup.rb

index = 0

while index < 1216623 do
  puts index

  sql = <<-SQL
    DELETE sv
      FROM share_visibilities AS sv
        INNER JOIN posts
        ON sv.shareable_id = posts.id
        WHERE sv.shareable_type = "Post"
          AND posts.public IS TRUE
          AND posts.id < #{index};
  SQL

  ActiveRecord::Base.connection.execute(sql)

  index += 100
end

We should make this a rake task.