Description of problem:
When ipa-client-install is run, it autodiscovers for existing LDAP servers and
checks if it is a valid IPA server. During the process, it tries to download
ca.crt. If the discovered target is unresponsive, ipa-client-install hangs and
does not let user to override the autodiscovered server/domain.

Version-Release number of selected component (if applicable):
ipa-client-2.1.1-101.20111004T0103zgita013597.el6.x86_64

How reproducible:
Have an LDAP server with proper _ldap._tcp DNS SRV records in client domain and
which would not return ca.crt (in my test it was ldap.corp.redhat.com) and run
ipa-client-install.


Steps to Reproduce:
1. Have the LDAP server with DNS SRV records as described
2. Run ipa-client-install without --server or --domain options

Actual results:
ipa-client-install hangs:

# ipa-client-install -d
root        : DEBUG    /usr/sbin/ipa-client-install was invoked with options:
{'conf_ntp': True, 'domain': None, 'uninstall': False, 'force': False, 'sssd':
True, 'krb5_offline_passwords': True, 'hostname': None, 'permit': False,
'server': None, 'prompt_password': False, 'mkhomedir': False, 'dns_updates':
False, 'debug': True, 'on_master': False, 'ntp_server': None, 'realm_name':
None, 'unattended': None, 'principal': None}
root        : DEBUG    missing options might be asked for interactively later

root        : DEBUG    Loading Index file from
'/var/lib/ipa-client/sysrestore/sysrestore.index'
root        : DEBUG    Loading StateFile from
'/var/lib/ipa-client/sysrestore/sysrestore.state'
root        : DEBUG    [ipadnssearchldap(idm.lab.bos.redhat.com)]
root        : DEBUG    [ipadnssearchldap(lab.bos.redhat.com)]
root        : DEBUG    [ipadnssearchldap(bos.redhat.com)]
root        : DEBUG    [ipadnssearchldap(redhat.com)]
root        : DEBUG    [ipadnssearchkrb]
root        : DEBUG    [ipacheckldap]


Expected results:
ipa-client-install should timeout, inform the user that the autodiscovery has
failed and let user enter his IPA server (which obviously does not have proper
DNS SRV records)