Fix follow limit preventing re-following of a moved account (#14207)

app/models/import.rb

@@ -27,6 +27,7 @@ class Import < ApplicationRecord
   enum type: [:following, :blocking, :muting, :domain_blocking, :bookmarks]
 
   validates :type, presence: true
+  validates_with ImportValidator, on: :create
 
   has_attached_file :data
   validates_attachment_content_type :data, content_type: FILE_TYPES