Update dependency rollup to v2.39.1

[renovate[bot]]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
rollup (source)	2.39.0 -> 2.39.1

---

Release Notes

rollup/rollup

### [`v2.39.1`](https://togithub.com/rollup/rollup/blob/master/CHANGELOG.md#​2391) [Compare Source](https://togithub.com/rollup/rollup/compare/v2.39.0...v2.39.1) _2021-02-23_ ##### Bug Fixes - Make sure local variables named Symbol, Object or Promise do not conflict with code generated by Rollup ([#​3971](https://togithub.com/rollup/rollup/issues/3971)) ##### Pull Requests - [#​3964](https://togithub.com/rollup/rollup/pull/3964): Remove extra word ([@​jamonholmgren](https://togithub.com/jamonholmgren)) - [#​3971](https://togithub.com/rollup/rollup/pull/3971): Avoid conflicts with local variables named Symbol, Object, Promise ([@​lukastaegert](https://togithub.com/lukastaegert))

---

Renovate configuration

:date: Schedule: At any time (no schedule defined).

:vertical_traffic_light: Automerge: Disabled by config. Please merge this manually once you are satisfied.

:recycle: Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

:no_bell: Ignore: Close this PR and you won't be reminded about this update again.

---

• [ ] If you want to rebase/retry this PR, check this box

---

This PR has been generated by WhiteSource Renovate. View repository job log here.