Remove double space in test name (#19762)

Author: gusaiani

packages/react/src/__tests__/ReactChildren-test.js

@@ -979,7 +979,7 @@ describe('ReactChildren', () => {
 );
 });
 
-it('does not warn when there are keys on elements in a fragment',()=>{
+it('does not warn when there are keys on elements in a fragment',()=>{
 classComponentReturningArrayextendsReact.Component{
 render(){
 return[<divkey="foo"/>,<divkey="bar"/>];