Default ldap search limit is now 30 sec by default during upgrade.
Limits must be changed for the whole ldap2 connection, because this
connection is used inside update plugins and commands called from
upgrade.
Together with increasing the time limit, also size limit should be
unlimited during upgrade. With sizelimit=None we may get the
TimeExceeded exception from getting default value of the sizelimit from LDAP.
https://fedorahosted.org/freeipa/ticket/5267
Reviewed-By: Jan Cholasta <jcholast@redhat.com>