small refactor of emailUtilities. splitParticipants method

javascript/src/utilities/emailUtilities.js

 import dataUriToBlob from "data-uri-to-blob";
 import libmime from 'libmime';
-import map from 'lodash/map';
 import union from 'lodash/union';
 
 import {
@@ -18,7 +17,7 @@ const SIGNATURE_CONTENT_TYPE = "application/pkcs7-signature";
 export const DEFAULT_ATTACHMENT_NAME = 'attachment';
 
 const splitParticipants = participantsList => {
-  const participants = map(participantsList, participants => participants.split(",").map(p => p.trim()));
+  const participants = participantsList.map(participants => participants.split(",").map(p => p.trim()));
   return union.apply(null, participants);
 };