Fix ES6 space-in-parens eslint rule [MAILPOET-1082]

.eslintrc.es6.json

@@ -51,7 +51,6 @@
     "block-scoped-var": 0,
     "no-extra-bind": 0,
     "class-methods-use-this": 0,
-    "space-in-parens": 0,
     "no-case-declarations": 0,
     "array-bracket-spacing": 0,
     "no-else-return": 0,

assets/js/src/newsletters/breadcrumb.jsx

@@ -57,7 +57,7 @@ define(
               <span className={stepClasses}>
                 { label }
               </span>
-              { (index < (this.state.steps.length - 1) ) ? ' > ' : '' }
+              { (index < (this.state.steps.length - 1)) ? ' > ' : '' }
             </span>
           );
         });