message: [ci][circleci] fix rustup command
  Closes:
  Approved by: rexhoffman
diff: @@ -71,7 +71,7 @@ commands:
  export CARGOFLAGS=$(cat cargo-flags)
  echo 'export CARGOFLAGS='${CARGOFLAGS} >> $BASH_ENV
  # Use nightly version of cargo to access the new feature resolver
  - echo 'export CARGO=$(rustup which --toolchain $RUST_NIGHTLY cargo)' >> $BASH_ENV
  + echo 'export CARGO=$(rustup which cargo --toolchain $RUST_NIGHTLY)' >> $BASH_ENV
  # Turn on the experimental feature resolver in cargo. See:
  install_code_coverage_deps:
  steps:
  