Fix react/jsx-indent-props rule in ES6

[MAILPOET-1029]

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

@@ -346,8 +346,8 @@ const _MailerMixin = {
         <p>{ mailer_check_settings_notice }</p>
         <p>
           <a href="javascript:;"
-             className="button"
-             onClick={ this.resumeMailerSending }
+            className="button"
+            onClick={ this.resumeMailerSending }
           >{ MailPoet.I18n.t('mailerResumeSendingButton') }</a>
         </p>
       </div>

assets/js/src/newsletters/send.jsx

@@ -301,17 +301,17 @@ define(
                 {
                   isPaused ?
                   <input
-                  className="button button-primary"
-                  type="button"
-                  onClick={ this.handleResume }
-                  value={MailPoet.I18n.t('resume')} />
+                    className="button button-primary"
+                    type="button"
+                    onClick={ this.handleResume }
+                    value={MailPoet.I18n.t('resume')} />
                   :
                   <input
-                  className="button button-primary"
-                  type="button"
-                  onClick={ this.handleSend }
-                  value={MailPoet.I18n.t('send')}
-                  {...this.getSendButtonOptions()}
+                    className="button button-primary"
+                    type="button"
+                    onClick={ this.handleSend }
+                    value={MailPoet.I18n.t('send')}
+                    {...this.getSendButtonOptions()}
                   />
                 }
                 &nbsp;