Re-enable clippy rule field_reassign_with_default

[webmaster128]

field_reassign_with_default was enabled with Rust 1.49.0 and does not play well with auto-generated code from schemars. See

• JsonSchema derive + #[serde(default)] triggers clippy lint in Rust 1.49 GREsau/schemars#69
• Fix clippy field_reassign_with_default in generated code GREsau/schemars#65

In order to allow developing with Rust 1.49.0, we added a few #![allow(clippy::field_reassign_with_default)]. Those should be removed when there is a schemars patch.

For contract developers it is recommended to use Rust stable 1.47.0 or 1.48.0 in order to avoid running into this problem again and again across different repos.

[webmaster128]

The fix in clippy landed after Jan 3rd when 1.50.0 was tagged. So it will be shipped in 1.51.0.

I wonder to what degree this is a pain for contract developers because both Rust 1.49.0 and 1.50.0 are affected by the problem now and 1.50.0 is the min version for CosmWasm 0.14 development.

[webmaster128]

Can reproduce the problem with Rust 1.50.0 in this repo as well as cosmwasm-examples. Current Rust beta (1.51.0) fixes it.

We should make Rust 1.51.0 the min supported version for CosmWasm 0.14 to ensure contract developers do not run into this problem.

[maurolacy]

I don't think it's so impactful: It's a linter warning, it's clearly a bug, and it's easy to silence.

I agree we should move to Rust 1.51.0 asap, though.

[webmaster128]

I don't think it's so impactful: It's a linter warning, it's clearly a bug, and it's easy to silence.

Yeah, but it is a serious support issue. The error message from the linter is not that helpful and we can't assume contract developers understand the source issue and identify it as a linter bug.

[webmaster128]

This can be resolved by using schemars 0.8.1: https://github.com/GREsau/schemars/releases/tag/v0.8.1