[VOL-4290] Voltha go library updates for gRPC migration

Change-Id: I1aa2774beb6b7ed7419bc45aeb53fcae8a8ecda0
diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/wrappers.go b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/wrappers.go
index 597b862..05ccfb3 100644
--- a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/wrappers.go
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/wrappers.go
@@ -4,7 +4,8 @@
 package grpc_middleware
 
 import (
-	"golang.org/x/net/context"
+	"context"
+
 	"google.golang.org/grpc"
 )