This value contains a space separated list of the concentrator ids to
include in the config response. If it is empty or not set, it will
default to return all concentrators. Due to the implementation it is
currently only possible to use concentrator ids between 1 and 64.

The python implementation replaced whitespaces with a +, but it looks
like this was just caused by an implementation bug. Go correctly parses
the %2B to a + sign, therefore not requiring an additional replace

The pubkey iterator already needs to request all node infos and
usually the code using this function also wants to get the NodeInfo
for the pubkeys.
The current implementation is very inefficient, as the unmarshal
functionality currently cannot handle maps

This tool was primarely used as a quick check, if any node does not
override the retry value in etcd. Because for every new node the retry
value was set to 600 by the original python script while the default value
was set to 20. Before changing the default value and removing all
overrides, this tool was created to check, if this would affect any node

also formatted the go code via go fmt