Add eslit rule `one-var`

.eslintrc

client/startup/userSetUtcOffset.js

lib/fileUpload.js

...hat-file-upload/server/config/configFileUploadAmazonS3.js

...tchat-file-upload/server/config/configFileUploadGridFS.js

packages/rocketchat-file-upload/server/lib/requests.js

...ges/rocketchat-file-upload/server/methods/getS3FileUrl.js

...ketchat-integrations/client/views/integrationsOutgoing.js

packages/rocketchat-lib/lib/fileUploadRestrictions.js

packages/rocketchat-lib/server/functions/saveUser.js

packages/rocketchat-lib/server/functions/setUserAvatar.js

packages/rocketchat-lib/server/lib/PushNotification.js

packages/rocketchat-lib/server/lib/notifyUsersOnMessage.js

packages/rocketchat-lib/server/lib/sendEmailOnMessage.js

...s/rocketchat-lib/server/lib/sendNotificationsOnMessage.js

packages/rocketchat-lib/server/methods/updateMessage.js

packages/rocketchat-livechat/app/client/views/messages.js

packages/rocketchat-livechat/app/client/views/register.js

packages/rocketchat-message-snippet/server/requests.js

...hat-slackbridge/slashcommand/slackbridge_import.server.js