tools/tsort-modules: Small fix to pattern for `@flow strict`.
tools/tsort-modules: Small fix to pattern for `@flow strict`.

The pattern we had here wasn't able to recognize the new annotation
in `generatedEs3.js`.

vishwesh3/zulip-mobile,vishwesh3/zulip-mobile,vishwesh3/zulip-mobile,vishwesh3/zulip-mobile