Work around etcd/gRPC error weirdness, retract v3.2.4 (PR #166)

go.mod

@@ -3,17 +3,13 @@ module github.com/lytics/grid/v3
 go 1.16
 
 require (
-	github.com/coreos/go-semver v0.3.0 // indirect
-	github.com/coreos/go-systemd v0.0.0-20190719114852-fd7a80b32e1f // indirect
-	github.com/coreos/pkg v0.0.0-20180928190104-399ea9e2e55f // indirect
-	github.com/dustin/go-humanize v1.0.0 // indirect
 	github.com/golang/protobuf v1.5.2
 	github.com/lytics/retry v1.2.0
-	github.com/spf13/pflag v1.0.5 // indirect
-	go.etcd.io/etcd v0.0.0-20190917205325-a14579fbfb1a
-	go.etcd.io/etcd/client/v3 v3.5.0 // indirect
-	go.etcd.io/etcd/server/v3 v3.5.0 // indirect
+	go.etcd.io/etcd/client/pkg/v3 v3.5.0 // indirect
+	go.etcd.io/etcd/client/v3 v3.5.0
+	go.etcd.io/etcd/server/v3 v3.5.0
 	golang.org/x/net v0.0.0-20210405180319-a5a99cb37ef4
 	google.golang.org/grpc v1.38.0
-	gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 // indirect
 )
+
+retract v3.2.4 // contains a very bad bug