skip users database host update

app/models/carto/user_migration_import.rb

@@ -132,6 +132,7 @@ module Carto
     end
 
     def update_database_host
+      return if dry
       users.each do |user|
         Rollbar.info("Updating database conection for user #{user.username} to #{database_host}")
         user.database_host = database_host

services/user-mover/import_user.rb

@@ -530,6 +530,7 @@ module CartoDB
       end
 
       def update_database_retries(userid, username, db_host, db_name, retries = 1)
+        return if @options[:dry]
         update_database(userid, username, db_host, db_name)
       rescue => e
         @logger.error "Error updating database"