Auto merge of #9890 - ehuss:remove-z-force-warn, r=alexcrichton
Auto merge of #9890 - ehuss:remove-z-force-warn, r=alexcrichton

Fix `cargo fix --edition` on stable.

I accidentally missed the removal of a `-Zunstable-options` flag in #9800.  This prevented `cargo fix --edition` from working on stable/beta.

rustyhorde/cargo,eminence/cargo,rustyhorde/cargo,rust-lang/cargo,nipunn1313/cargo,nipunn1313/cargo,nipunn1313/cargo,rustyhorde/cargo,rust-lang/cargo,rustyhorde/cargo,rust-lang/cargo,nipunn1313/cargo,eminence/cargo,eminence/cargo,rust-lang/cargo,eminence/cargo