rust-mozjs

9241cdde - Auto merge of #480 - romankl:r-fix-deprecation-warnings, r=jdm

Auto merge of #480 - romankl:r-fix-deprecation-warnings, r=jdm fix deprecation warnings for `try!` and dyn traits this commit fixes some deprecation warnings that are caused by the old `try!`. Every part is replaced with the `?` operator. At one part the compiler mentioned the deprecation: ```bash trait objects without an explicit `dyn` are deprecated ``` which is also replaced. <!-- Reviewable:start --> --- This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/rust-mozjs/480) <!-- Reviewable:end -->