Fix notifications related to the cert section of the user details

[miskopo]

Problem description

User is not notified when there is an issue with certificate addition via user settings

Steps to reproduce:

1. create an user
2. open user details
3. in Certificates section, click on Add button
4. paste the valid certificate (see below) (certificate info should be visible)
5. click on Add button again
6. paste the same cert
7. click on Add button (no warning/error is shown, cert text box stays open)
8. delete the valid certificate
9. try to add invalid cert (random text) (no warning/error is shown, cert box stays open)

Expected behaviour:

User is notified about invalid/duplicate certificate

Actual behaviour:

no warning/error is shown, cert box stays open

Certificate used:

-----BEGIN CERTIFICATE-----
  MIIHUzCCBTugAwIBAgIRAMbkmDZJZqhTAAAAAFZl8D0wDQYJKoZIhvcNAQELBQAw
  RDELMAkGA1UEBhMCSFIxHTAbBgNVBAoTFEZpbmFuY2lqc2thIGFnZW5jaWphMRYw
  FAYDVQQDEw1GaW5hIFJEQyAyMDE1MB4XDTE5MTAxNDEyMTMyMFoXDTIxMTAxNDEy
  MTMyMFowgakxCzAJBgNVBAYTAkhSMRQwEgYDVQQKEwtIT1BTIEQuTy5PLjEWMBQG
  A1UEYRMNSFIxMzE0ODgyMTYzMzEPMA0GA1UEBxMGWkFHUkVCMQ8wDQYDVQQEEwZI
  Uk5KQUsxEjAQBgNVBCoTCUtSVU5PU0xBVjEZMBcGA1UEAxMQS1JVTk9TTEFWIEhS
  TkpBSzEbMBkGA1UEBRMSSFI1NzI4OTI5NDg5NC4yLjIxMIIBIjANBgkqhkiG9w0B
  AQEFAAOCAQ8AMIIBCgKCAQEAig6HRn4uUvbUgFltOqWWo5OLnoWyuc6pAtBdaj+U
  z3TM06ZVJtpnEsPsYPZ3iRLSUWz4ymkc+uv9YeWSbpOo0ft6UQ4HYN155DchpSgX
  ycwgiJXMCyic61RcX05xNXfdnm4gJOeh8E46P3IEb2wKEj5rYe5Uk/ZJ59cPNu1e
  4rPKMTUH835awkyRCh1jWCXzWDowp8dl7kzroaotwRrJdxeL0taopyc9abUUm6kG
  fTkdUbBw9uvFKq/uDJl+6IjmW2cMu8ZSPSctBDVEbySWk6yHW0ZXs+xvD+NYgBZT
  8Mqzc8LFhHT3ERYjf2JfZuWwQ9ODAfQOZr5nS5Me3hGWRwIDAQABo4IC2DCCAtQw
  DgYDVR0PAQH/BAQDAgWgMB0GA1UdJQQWMBQGCCsGAQUFBwMEBggrBgEFBQcDAjCB
  sAYDVR0gBIGoMIGlMIGYBgkrfIhQBQwMBAIwgYowQwYIKwYBBQUHAgEWN2h0dHA6
  Ly9yZGMuZmluYS5oci9SREMyMDE1L0ZpbmFSREMyMDE1LUNQU05RQzEtMy1oci5w
  ZGYwQwYIKwYBBQUHAgEWN2h0dHA6Ly9yZGMuZmluYS5oci9SREMyMDE1L0ZpbmFS
  REMyMDE1LUNQU05RQzEtMy1lbi5wZGYwCAYGBACPegECMGkGCCsGAQUFBwEBBF0w
  WzAfBggrBgEFBQcwAYYTaHR0cDovL29jc3AuZmluYS5ocjA4BggrBgEFBQcwAoYs
  aHR0cDovL3JkYy5maW5hLmhyL1JEQzIwMTUvRmluYVJEQ0NBMjAxNS5jZXIwIwYD
  VR0RBBwwGoEYa3J1bm9zbGF2Lmhybmpha0Bob3BzLmhyMIIBEwYDVR0fBIIBCjCC
  AQYwgaSggaGggZ6GLGh0dHA6Ly9yZGMuZmluYS5oci9SREMyMDE1L0ZpbmFSREND
  QTIwMTUuY3Jshm5sZGFwOi8vcmRjLWxkYXAyLmZpbmEuaHIvY249RmluYSUyMFJE
  QyUyMDIwMTUsbz1GaW5hbmNpanNrYSUyMGFnZW5jaWphLGM9SFI/Y2VydGlmaWNh
  dGVSZXZvY2F0aW9uTGlzdCUzQmJpbmFyeTBdoFugWaRXMFUxCzAJBgNVBAYTAkhS
  MR0wGwYDVQQKExRGaW5hbmNpanNrYSBhZ2VuY2lqYTEWMBQGA1UEAxMNRmluYSBS
  REMgMjAxNTEPMA0GA1UEAxMGQ1JMNzUxMB8GA1UdIwQYMBaAFBRjEbt7MwNodBwV
  7eYswTxIG5ghMB0GA1UdDgQWBBTsd+TYygvZpCDO4kDpEnMKUkZOfTAJBgNVHRME
  AjAAMA0GCSqGSIb3DQEBCwUAA4ICAQBIhFElngJOz+K+Q1FZLhEVLngMI92k858M
  W6WHJ17SXhiR/m/ESOM5mVkOyiOQoM1po1I/jdUjE2mHHjiT12tJgkavkDxXz6aX
  hKdj9VDVnzSp0wRvzIgQKWJF0JO82umt0I9x265cGXmRnRjxnDbEmgGKdFeSTbkp
  gJfk73rdRbkIEI7FoOIzuaIRcHRIREkfUltu/1zD+bCMSY2pFA/0FQ15dFUDAeiD
  6gqyjZgJJC5Rqd6SuMLfF4aAmz7FBgpk7iVm5jGRPltHCK3aH7OEczsDi1fYVtRA
  PdRvKlzqbajv6Qj0YICMg3byh3ObN5xZp4qQmxGu9w7sJioMRP7DxxMuQKx4byV2
  O0Jo7cdnc6BXfR+EipXz/phExWvRKwSOaelweOZUjz9sffpNYmvfuqmGhL5axNtj
  XQmAJ1wOo8m7j4Czz7m7WFtxdiZ0SYGBxnr0xpCJrHgxLU640a/T/vDPh/SSai5S
  E4unGGIf6vT0+5KY2gU6Jly7pqKpc44FHFrOdhWTEZzbmaiGL2QMh8VE2bAV9dNp
  YT7djK+WY554vVLE3N7M21qiCNxD5awuIEkpZoF1d7A/wMgAe40ZMZ6UbYawzAPf
  Tca3LXBLJOR4Ox2ZEbFt/JlIe7pZqR67s628axLaKCdQhOLP77KsNPMahzjQ7JmR
  znZSOnBy/Q==
  -----END CERTIFICATE-----

Test coverage:

This issue is covered by scenario Certificates - addition from user_details.feature