Backport FIX manage event in select_company with AJAX search option on

[uvaldenaire-opendsi]

Backport of #18253

[eldy]

Can you remind me how to reproduce the bug ?

[uvaldenaire-opendsi]

In third parties config page put COMPANY_USE_SEARCH_TO_SELECT to at least 1.
This is the field: "Wait until a key is pressed before loading content of Third Parties combo list".

Then go to create new event. Select a third party (Related company) .

The third party contacts should now be in "Related contact" select field. But they are not.

Also, if you set CONTACT_USE_SEARCH_TO_SELECT to at least one in the third parties config page,
(The field "Wait until a key is pressed before loading content of Contact combo list.")
and type the begining of a contact name, the contact don't appear in the options.