diff --git a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/util/metautils/nicemd.go b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/util/metautils/nicemd.go
index a277bee..1c60585 100644
--- a/vendor/github.com/grpc-ecosystem/go-grpc-middleware/util/metautils/nicemd.go
+++ b/vendor/github.com/grpc-ecosystem/go-grpc-middleware/util/metautils/nicemd.go
@@ -4,9 +4,9 @@
 package metautils
 
 import (
+	"context"
 	"strings"
 
-	"golang.org/x/net/context"
 	"google.golang.org/grpc/metadata"
 )
 
@@ -49,7 +49,7 @@
 			found = true
 		} else {
 			for _, allowedKey := range copiedKeys {
-				if strings.ToLower(allowedKey) == strings.ToLower(k) {
+				if strings.EqualFold(allowedKey, k) {
 					found = true
 					break
 				}
@@ -83,7 +83,7 @@
 //
 // The function is binary-key safe.
 func (m NiceMD) Get(key string) string {
-	k, _ := encodeKeyValue(key, "")
+	k := strings.ToLower(key)
 	vv, ok := m[k]
 	if !ok {
 		return ""
@@ -98,7 +98,7 @@
 // The function is binary-key safe.
 
 func (m NiceMD) Del(key string) NiceMD {
-	k, _ := encodeKeyValue(key, "")
+	k := strings.ToLower(key)
 	delete(m, k)
 	return m
 }
@@ -109,8 +109,8 @@
 //
 // The function is binary-key safe.
 func (m NiceMD) Set(key string, value string) NiceMD {
-	k, v := encodeKeyValue(key, value)
-	m[k] = []string{v}
+	k := strings.ToLower(key)
+	m[k] = []string{value}
 	return m
 }
 
@@ -120,7 +120,7 @@
 //
 // The function is binary-key safe.
 func (m NiceMD) Add(key string, value string) NiceMD {
-	k, v := encodeKeyValue(key, value)
-	m[k] = append(m[k], v)
+	k := strings.ToLower(key)
+	m[k] = append(m[k], value)
 	return m
 }