Merge pull request #3627 from spicyj/mut-warn-clone

Refer to cloneElement in mutation warning

src/classic/element/ReactElementValidator.js

@@ -302,9 +302,9 @@ function warnForPropsMutation(propName, element) {
 
   warning(
     false,
-    'Don\'t set .props.%s of the React component%s. ' +
-    'Instead, specify the correct value when ' +
-    'initially creating the element.%s',
+    'Don\'t set .props.%s of the React component%s. Instead, specify the ' +
+    'correct value when initially creating the element or use ' +
+    'React.cloneElement to make a new element with updated props.%s',
     propName,
     elementInfo,
     ownerInfo