ipaserver/library/ipaserver_test: adtrust message should be warning

Tee message for a domain and realm name mismatch should be a warning and
not a fail in the ipaserver test. It is also a warning in the normal
installer.

roles/ipaserver/library/ipaserver_test.py

@@ -578,8 +578,8 @@ def main():
         # to establish trust with Active Directory. Fail.
 
         if options.domain_name.upper() != options.realm_name:
-            ansible_module.fail_json(
-                msg="Realm name does not match the domain name: "
+            ansible_module.warn(
+                "Realm name does not match the domain name: "
                 "You will not be able to establish trusts with Active "
                 "Directory.")