tools: disable SSSD's locator plugin
MIT's libkrb5 checks available locator plugins first before checking the config file. This might cause issues when the locator plugin returns a different DC than the one used for the LDAP connection if some data must be replicated.
This patch sets the SSSD_KRB5_LOCATOR_DISABLE environment variable to 'true' to disable SSSD's locator plugin for adcli.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1762633