agent/config: default connect enabled in dev mode

This enables `consul agent -dev` to begin using Connect features with
the built-in CA. I think this is expected behavior since you can imagine
that new users would want to try.

There is no real downside since we're just using the built-in CA.

agent/config/default.go

@@ -108,6 +108,10 @@ func DevSource() Source {
 		ui = true
 		log_level = "DEBUG"
 		server = true
+
+		connect = {
+			enabled = true
+		}
 		performance = {
 			raft_multiplier = 1
 		}

agent/config/runtime_test.go

@@ -263,6 +263,7 @@ func TestConfigFlagsAndEdgecases(t *testing.T) {
 				rt.AdvertiseAddrLAN = ipAddr("127.0.0.1")
 				rt.AdvertiseAddrWAN = ipAddr("127.0.0.1")
 				rt.BindAddr = ipAddr("127.0.0.1")
+				rt.ConnectEnabled = true
 				rt.DevMode = true
 				rt.DisableAnonymousSignature = true
 				rt.DisableKeyringFile = true