Add GossipOverHttps option to EventStoreClientConnectivitySettings

[shaan1337]

Fixes #50

This PR allows the dotnet gRPC client to connect to a cluster running with --insecure (related PR: EventStore/EventStore#2556)

[hayley-jean]

Looks good and I've tested locally. I just have one comment about the naming of UseHttps

[hayley-jean]

Perhaps we should rename UseHttps to make it more obvious that it only applies to gossip seeds, as it doesn't affect single node connection defaults right now.

As it stands, it looks like I could use the following to connect to a single node running with defaults and --insecure:

ConnectivitySettings =
{
    UseHttps = false
}

But the above results in SSL errors. I have to set the uri instead :

ConnectivitySettings =
{
    Address = new Uri("http://localhost:2113")
}

[thefringeninja]

The other thing we can do here is infer that from Address.

[shaan1337]

@hayley-jean @thefringeninja good catch thanks , i'll try to see if we can infer it from Address so that it can be used both for single nodes and clusters

[shaan1337]

@hayley-jean @thefringeninja what do you think about:

		private bool _useHttps = true;
		public bool UseHttps {
			get{
				return _useHttps;
			}
			set{
				_useHttps = value;
				Address = new UriBuilder{
					Scheme = _useHttps ? Uri.UriSchemeHttps : Uri.UriSchemeHttp,
					Host = Address.Host,
					Port = Address.Port
				}.Uri;
			}
		}

the good thing is that it would modify the Address only if UseHttps is set by the user

[shaan1337]

@hayley-jean @thefringeninja after discussing with @pgermishuys , GossipOverHttps might be a better name - technically speaking, it is not completely valid since we also use the flag to connect the the node (not only for gossip info) but it seems more intuitive from a user perspective and is consistent with GossipSeeds and GossipTimeout options

[shaan1337]

Fixed in this commit: 983861d