Set KRB5_CONFIG earlier in check-ldap

Otherwise the kdc won't find the plugin.

tests/ldap/check-ldap.in

@@ -52,6 +52,9 @@ kdc="${TESTS_ENVIRONMENT} ../../kdc/kdc --addresses=localhost -P $port"
 
 testfailed="echo test failed; exit 1"
 
+KRB5_CONFIG="${objdir}/krb5.conf"
+export KRB5_CONFIG
+
 # If there is no ldap support compile in, disable test
 if ${kdc} --builtin-hdb | grep ldap > /dev/null ; then
    :
@@ -84,9 +87,6 @@ sh ${objdir}/slapd-init || exit 1
 
 trap "sh ${srcdir}/slapd-stop ; exit 1;" EXIT
 
-KRB5_CONFIG="${objdir}/krb5.conf"
-export KRB5_CONFIG
-
 rm -f current-db*
 
 > messages.log