not clean auth params

[GoogleCodeExporter]

What steps will reproduce the problem?
1. set key line as 
mikoomi-mongodb-plugin.sh["--", "-h", "{$MONGODB_HOSTNAME}", "-p", 
"{$MONGODB_PORT}", "-z", "{$MONGODB_ZABBIX_NAME}", "-u", "{$MONGODB_USER}", 
"-x", "{$MONGODB_PASS}"]
2. don't set in Template Macros optional parameters
$MONGODB_USER and $MONGODB_PASS
3.

What is the expected output? What do you see instead?
Suppose it to connect without login/pass authentification
but instead there just no reaction in logs and "no data" on output

What version of the product are you using? On what operating system?
Linux 3.2
tryed svn-version
http://mikoomi.googlecode.com/svn/plugins/MongoDB%20Plugin/
and patched version from
http://code.google.com/p/mikoomi/issues/detail?id=6

Please provide any additional information below.
Some time one Template may be used to monitor Authentificated and 
non-Authentificated bases (or bases may change auth params).
I think script should ignore empty params.

Original issue reported on code.google.com by b...@rackit.dp.ua on 14 Aug 2012 at 2:16