fix ldapsearch command

[bhallasaksham]

Description of changes:
ldapsearch command on ubuntu distros works when we provide -N flag. A corresponding change in /etc/krb5.conf to set rdns - false was also made to get the gmsa_test_client working for ubuntu distros

root@ip-10-0-2-67:/home/ubuntu# cat /etc/krb5.conf 
[libdefaults]
	default_realm = CONTOSO.COM
	rdns = false

Testing done:
ran the gmsa_test_client on ubuntu with this credspec on an ubuntu instance and verified that lease was created successfully.

(venv) root@ip-10-0-2-67:/home/ubuntu/credentials-fetcher/protos# python3 credentials_fetcher_client.py 
Server response: lease_id: "a8111a49d9cab0293c64"
created_kerberos_file_paths: "/var/credentials-fetcher/krbdir/a8111a49d9cab0293c64/WebApp01"

(venv) root@ip-10-0-2-67:/home/ubuntu/credentials-fetcher/protos# cat credentials_fetcher_client.py 
import grpc
import credentialsfetcher_pb2
import credentialsfetcher_pb2_grpc

def run():
    with grpc.insecure_channel('unix:///var/credentials-fetcher/socket/credentials_fetcher.sock') as channel:
        stub = credentialsfetcher_pb2_grpc.CredentialsFetcherServiceStub(channel)
        credspec_contents="{\"CmsPlugins\":[\"ActiveDirectory\"],\"DomainJoinConfig\":{\"Sid\":\"S-1-5-21-2725122404-4129967127-2630707939\",\"MachineAccountName\":\"WebApp01\",\"Guid\":\"e96e0e09-9305-462f-9e44-8a8179722897\",\"DnsTreeName\":\"contoso.com\",\"DnsName\":\"contoso.com\",\"NetBiosName\":\"contoso\"},\"ActiveDirectoryConfig\":{\"GroupManagedServiceAccounts\":[{\"Name\":\"WebApp01\",\"Scope\":\"contoso.com\"},{\"Name\":\"WebApp01\",\"Scope\":\"contoso\"}], \"HostAccountConfig\": {\"PortableCcgVersion\": \"1\",\"PluginGUID\": \"{GDMA0342-266A-4D1P-831J-20990E82944F}\",\"PluginInput\": {\"CredentialArn\": \"aws/directoryservice/contoso/gmsa\"}}}"
        contents = []
        contents += [credspec_contents]
        response = stub.AddNonDomainJoinedKerberosLease(credentialsfetcher_pb2.CreateNonDomainJoinedKerberosLeaseRequest(credspec_contents = contents, username="standarduser01", password="p@ssw0rd", domain="contoso.com"))
        print(f"Server response: {response}")

if __name__ == '__main__':
  run()

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