Password on external resource not updated via Enduser

As reported in mailing list, the issue can be replicated with standalone distribution / embedded mode:

1. from Admin Console, create user ilgrosso@apache.org, set Password123 as password value and assign `resource-ldap`
2. user is successfully created and propagated
3. binding via LDAP works fine with the password set above:

   ldapsearch -h localhost -p 1389 -D "uid=ilgrosso@apache.org,ou=People,o=isp" -x -w Password123 -b "uid=ilgrosso@apache.org,ou=People,o=isp"
    

4. from Admin Console, update the user above by setting the password to Password124
5. binding via LDAP works fine with updated password:

   ldapsearch -h localhost -p 1389 -D "uid=ilgrosso@apache.org,ou=People,o=isp" -x -w Password124 -b "uid=ilgrosso@apache.org,ou=People,o=isp"
    

6. from Enduser UI, login as ilgrosso@apache.org / Password124 and set the password to Password125

At this point:

• Password125 is set on Syncope
• Password124 is still set on LDAP
• a DELETE propagation task was created as consequence of Enduser UI password change