gRPC migration

Change-Id: Ib390f6dde0d5a8d6db12ccd7da41135570ad1354
diff --git a/vendor/google.golang.org/grpc/internal/envconfig/envconfig.go b/vendor/google.golang.org/grpc/internal/envconfig/envconfig.go
index ae6c897..3ee8740 100644
--- a/vendor/google.golang.org/grpc/internal/envconfig/envconfig.go
+++ b/vendor/google.golang.org/grpc/internal/envconfig/envconfig.go
@@ -25,14 +25,11 @@
 )
 
 const (
-	prefix          = "GRPC_GO_"
-	retryStr        = prefix + "RETRY"
-	txtErrIgnoreStr = prefix + "IGNORE_TXT_ERRORS"
+	prefix   = "GRPC_GO_"
+	retryStr = prefix + "RETRY"
 )
 
 var (
 	// Retry is set if retry is explicitly enabled via "GRPC_GO_RETRY=on".
 	Retry = strings.EqualFold(os.Getenv(retryStr), "on")
-	// TXTErrIgnore is set if TXT errors should be ignored ("GRPC_GO_IGNORE_TXT_ERRORS" is not "false").
-	TXTErrIgnore = !strings.EqualFold(os.Getenv(retryStr), "false")
 )