tools: fix example in configuration file.

The SNMP_MANAGERS example contains space and no quotes. Users
following this example will lose all but first snmp managers.

Change-Id: I30de620597eba51a0955d0d6c5cd1c4232c1ab44
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1074431
Signed-off-by: Mooli Tayer <mtayer@redhat.com>