fail of email update

[Luci2015]

Description
Updating emails of accounts that have usernames in non-email formatted values fails with latest version of the tool

Steps to reproduce

• Relevant config options

• update_user_info: True
• make sure you have an account in admin console with username in non-email format and attempt to update the LDAP attribute of mail to some other value on same domain
  After the tool runs, it recognises the mail should be updated but the value it uses for 'user' in the json body is the new email, not the current email of the existing account to target the update on it

Expected behavior
email should be updated

Screenshots

Environment

• UST version: >= 2.9.0
• OS type and version: all