Fix accidental reversion of submodules.

[td202]

Purpose

When merging 6.3.1 hotfix, submodule dependencies were accidentally reverted to earlier versions. This restores them.

Changes

• Update concordium-base and haskell-lmdb submodules as they were before the merge of Hotfix 6.3.1 #1198

Checklist

• My code follows the style of this project.
• The code compiles without warnings.
• I have performed a self-review of the changes.
• I have documented my code, in particular the intent of the
  hard-to-understand areas.
• (If necessary) I have updated the CHANGELOG.