[krbdev.mit.edu #8274] LDAP KDB module hardcodes 10-second connection timeout

[Greg Hudson via RT]

krb5_ldap_db_init() sets LDAP_OPT_NETWORK_TIMEOUT (or 
LDAP_X_OPT_CONNECT_TIMEOUT) to a hardcoded value of ten seconds, with 
no configuration setting to override it.

We should either provide a configuration option to set the timeout, or 
let the LDAP library choose the timeout.