Fix IPv6 address being sent to `gethostname` still containing []'s

[aashah]

IPv6 addresses can have brackets around their host, this causes issues here:

nats.rb/lib/nats/client.rb

Line 229 in 1bb2325

client = EM.connect(@uri.host, @uri.port, self, opts)

where EM.connect() eventually goes down to a gethostname call.

Simple hack is to update that to something like: EM.connect(@uri.host.tr('[]', '') ....

I'm not sure what the right thing to do here is, would love help figuring out if this issue is in the right place too. Is this a problem ruby's uri, and stripping [] from some_uri.host?