fix a small typo in pingpong api test comment

pkg/api/pingpong_test.go

@@ -64,7 +64,7 @@ func TestPingpong(t *testing.T) {
 	t.Run("error", func(t *testing.T) {
 		jsonhttptest.ResponseDirect(t, client, http.MethodPost, "/pingpong/"+errorPeerID.String(), nil, http.StatusInternalServerError, jsonhttp.StatusResponse{
 			Code:    http.StatusInternalServerError,
-			Message: http.StatusText(http.StatusInternalServerError), // do not leek internal error
+			Message: http.StatusText(http.StatusInternalServerError), // do not leak internal error
 		})
 	})