Fix ESLint no-multipe-empty-lines ES6

[MAILPOET-1031]

.eslintrc.es6.json

@@ -60,7 +60,6 @@
     "no-multi-spaces": 0,
     "class-methods-use-this": 0,
     "key-spacing": 0,
-    "no-multiple-empty-lines": 0,
     "space-in-parens": 0,
     "no-case-declarations": 0,
     "array-bracket-spacing": 0,

assets/js/src/newsletters/listings/mixins.jsx

@@ -374,8 +374,6 @@ const _MailerMixin = {
 };
 
 
-
-
 export { _QueueMixin as QueueMixin };
 export { _StatisticsMixin as StatisticsMixin };
 export { _MailerMixin as MailerMixin };