Put 'this' in 'self' variable

For some reason, TrelloCreator didn't keep 'this' reference

models/trelloCreator.js

@@ -318,11 +318,12 @@ export class TrelloCreator {
           // - HEAD returns null, which causes exception down the line
           // - the template then tries to display the url to the attachment which causes other errors
           // so we make it server only, and let UI catch up once it is done, forget about latency comp.
+          const self = this;
           if(Meteor.isServer) {
             file.attachData(att.url, function (error) {
               file.boardId = boardId;
               file.cardId = cardId;
-              file.userId = this._user(att.idMemberCreator);
+              file.userId = self._user(att.idMemberCreator);
               // The field source will only be used to prevent adding
               // attachments' related activities automatically
               file.source = 'import';
@@ -332,7 +333,7 @@ export class TrelloCreator {
                 const wekanAtt = Attachments.insert(file, () => {
                   // we do nothing
                 });
-                this.attachmentIds[att.id] = wekanAtt._id;
+                self.attachmentIds[att.id] = wekanAtt._id;
                 //
                 if(trelloCoverId === att.id) {
                   Cards.direct.update(cardId, { $set: {coverId: wekanAtt._id}});

models/wekanCreator.js

@@ -307,12 +307,13 @@ export class WekanCreator {
           // - HEAD returns null, which causes exception down the line
           // - the template then tries to display the url to the attachment which causes other errors
           // so we make it server only, and let UI catch up once it is done, forget about latency comp.
+          const self = this;
           if(Meteor.isServer) {
             if (att.url) {
               file.attachData(att.url, function (error) {
                 file.boardId = boardId;
                 file.cardId = cardId;
-                file.userId = this._user(att.userId);
+                file.userId = self._user(att.userId);
                 // The field source will only be used to prevent adding
                 // attachments' related activities automatically
                 file.source = 'import';
@@ -322,7 +323,7 @@ export class WekanCreator {
                   const wekanAtt = Attachments.insert(file, () => {
                     // we do nothing
                   });
-                  this.attachmentIds[att._id] = wekanAtt._id;
+                  self.attachmentIds[att._id] = wekanAtt._id;
                   //
                   if(wekanCoverId === att._id) {
                     Cards.direct.update(cardId, { $set: {coverId: wekanAtt._id}});
@@ -334,7 +335,7 @@ export class WekanCreator {
                 file.name(att.name);
                 file.boardId = boardId;
                 file.cardId = cardId;
-                file.userId = this._user(att.userId);
+                file.userId = self._user(att.userId);
                 // The field source will only be used to prevent adding
                 // attachments' related activities automatically
                 file.source = 'import';