submodules: bump external/cli from 1b97709 to 91cc5e7

Bumps [external/cli](https://github.com/oasisprotocol/cli) from `1b97709` to `91cc5e7`.
- [Release notes](https://github.com/oasisprotocol/cli/releases)
- [Commits](oasisprotocol/cli@1b97709...91cc5e7)

---
updated-dependencies:
- dependency-name: external/cli
  dependency-type: direct:production
...

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