Rollup merge of rust-lang#75426 - ehuss:update-cargo, r=ehuss

Update cargo

7 commits in 1653f354644834073d6d2541e27fae94588e685e..ab32ee88dade1b50c77347599e82ca2de3fb8a51
2020-08-04 23:14:37 +0000 to 2020-08-10 17:44:43 +0000
- Build manpage archive deterministically (rust-lang/cargo#8600)
- doc: Qualify GNU licenses in example license field (rust-lang/cargo#8604)
- Fix jobserver_exists test on single-cpu systems (rust-lang/cargo#8598)
- Fix small typo in reference/profiles.md (rust-lang/cargo#8605)
- Default cargo publish to the alt registry if it's the only allowed one (rust-lang/cargo#8571)
- cargo install with specific yanked version gives confusing "not found" error (rust-lang/cargo#8565)
- Fix typo (rust-lang/cargo#8589)