wintest Force krb5.conf for BIND so we use the one generated for this test

This avoids needing to set the krb5.conf for the whole host to match
the test environment.

Andrew Bartlett

wintest/test-s4-howto.py

@@ -12,7 +12,7 @@ def check_prerequesites(t):
     if os.getuid() != 0:
         raise Exception("You must run this script as root")
     t.cmd_contains("grep 127.0.0.1 /etc/resolv.conf", ["nameserver 127.0.0.1"])
-
+    t.putenv("KRB5_CONFIG", '${PREFIX}/private/krb5.conf')
 
 def build_s4(t):
     '''build samba4'''