Fix segfault with Solaris LDAP SDK when enabling ldaps.

Enable SSL by passing secure=1 to apr_ldap_init instead of calling
apr_ldap_set_option(... APR_LDAP_OPT_TLS ...).

This change carefully avoids any change of behavior on non-Solaris LDAP SDKs.

PR: 42682


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1209601 13f79535-47bb-0310-9956-ffa450edef68