Trim errmap doc strings

[macalinao]

Motivation

Errmap strings have extra leading spaces in them.

Have you read the Contributing Guidelines on pull requests?

Yes

Test Plan

N/A

[sblackshear]

I think you will need to run cargo build in move-stdlib to update the errmap for the stdlib to one without these extra spaces.

[wrwg]

You'd need to cd language/move-stdlib && cargo run to regenerate the errrmap for stdlib to make the tests pass.

[wrwg]

This was done now in the aptos repo (which has a copy of error map gen).