v-model: do not fire listener at compositionend in lazy mode (fix #1327)

src/directives/model/text.js

@@ -32,7 +32,11 @@ module.exports = {
         // in IE11 the "compositionend" event fires AFTER
         // the "input" event, so the input handler is blocked
         // at the end... have to call it here.
-        self.listener()
+        //
+        // #1327: in lazy mode this is unecessary.
+        if (!lazy) {
+          self.listener()
+        }
       })
     }