Bump gui-v2 from 66d0389 to b15b32a

Bumps [gui-v2](https://github.com/OpenEVSE/openevse-gui-v2) from `66d0389` to `b15b32a`.
- [Commits](OpenEVSE/openevse-gui-v2@66d0389...b15b32a)

---
updated-dependencies:
- dependency-name: gui-v2
  dependency-version: b15b32a2720827b9bd53521cce8dbbc5bc9a1503
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]