Ruby on Rails

i have created a web app with rails4 and authentication system is developed with devise_ldap_authenticable gem. where i am using username for login not email. but i want to store email in my users table. My user model is

 class User < ActiveRecord::Base

# Include default devise modules. Others available are:  # :confirmable, :lockable, :timeoutable and :omniauthable  #@attr_accessible :email, :password, :password_confirmation  # not required for LDAP :recoverable, :registerable, :validatable  devise :ldap_authenticatable, :rememberable, :trackable    validates_uniqueness_of :email, :allow_blank => true     before_save :get_ldap_email     def get_ldap_email    self.email = Devise::LDAP::Adapter.get_ldap_param(self.username, "mail")   end  end 

But in users table of email field its storing data like

`email` = '--- !ruby/array:Net::BER::BerIdentifiedArray\ninternal:\n- !ruby/string:Net::BER::BerIdentifiedString\n str: !binary |-\n cy5naG9zaEBzYW1zdW5nLmNvbQ==\n ber_identifier: 4\nivars:\n :@ber_identifier: 49\n'
log says, LDAP: Requested param mail has value ["s.g...@example.com"]
How i will store this value to my users table. where im doing wrong? please help me out.