Point imports to new gotapdance repo

- Temporary vendor patch.

vendor/github.com/refraction-networking/gotapdance/tapdance/assets.go

@@ -13,7 +13,7 @@ import (
 	"sync"
 
 	"github.com/golang/protobuf/proto"
-	pb "github.com/sergeyfrolov/gotapdance/protobuf"
+	pb "github.com/refraction-networking/gotapdance/protobuf"
 )
 
 type assets struct {

vendor/github.com/refraction-networking/gotapdance/tapdance/conn_flow.go

@@ -18,8 +18,8 @@ import (
 	"time"
 
 	"github.com/golang/protobuf/proto"
+	pb "github.com/refraction-networking/gotapdance/protobuf"
 	"github.com/sergeyfrolov/bsbuffer"
-	pb "github.com/sergeyfrolov/gotapdance/protobuf"
 )
 
 // TapdanceFlowConn represents single TapDance flow.

vendor/github.com/refraction-networking/gotapdance/tapdance/conn_raw.go

@@ -17,8 +17,8 @@ import (
 	"time"
 
 	"github.com/golang/protobuf/proto"
+	pb "github.com/refraction-networking/gotapdance/protobuf"
 	"github.com/refraction-networking/utls"
-	pb "github.com/sergeyfrolov/gotapdance/protobuf"
 )
 
 // Simply establishes TLS and TapDance connection.