hooks/pre_start: Hide output

Avoid "erl" printing the following message to the standard output:

| Protocol 'inet_tcp': register/listen error: econnrefused

The happens because the node tries to talk to EPMD, which isn't running.
Could also be avoided by specifying e.g. "-erl_epmd_port 3470", but we'd
rather not assume a specific port being available on the target system.

overlay/hooks/pre_start

@@ -26,7 +26,7 @@ then
         -start_epmd 'false' \
         -sname 'cookie' \
         -eval 'halt()' \
-        2>'/dev/null' || :
+        >'/dev/null' 2>&1 || :
 
     if [ -r "$DEFAULT_COOKIE_FILE" ]
     then