stack.erp5: Accept relaying mail with addresses starting with a dash.

This simplistic mail setup does not pass address as command line arguments,
so it is not subject to the vulnerability protected against by this option.

stack/erp5/buildout.hash.cfg

@@ -63,7 +63,7 @@ md5sum = 9ac81647368068a1a98a785d08074b43
 
 [template-postfix-main-cf]
 filename = postfix_main.cf.in
-md5sum = 4fe9bb5225b9d7650d2916a0945821bd
+md5sum = 886d1b004049c8dc1f89cbbfe4f95371
 
 [template-postfix-aliases]
 filename = postfix_aliases.in

stack/erp5/postfix_main.cf.in

@@ -52,6 +52,10 @@ smtpd_relay_restrictions =
   permit_sasl_authenticated
   defer_unauth_destination
 
+# We do not pass mail address in command lines, so accept those starting with
+# a dash.
+allow_min_user = yes
+
 # Disable local delivery
 local_transport = error