message: actually use latest rustc in azure
diff: @@ -4,6 +4,7 @@ parameters:
  steps:
  - bash: |
  curl https://sh.rustup.rs -sSf | sh -s -- -y --default-toolchain $TOOLCHAIN
  + rustup update $TOOLCHAIN
  echo "##vso[task.setvariable variable=PATH;]$PATH:$HOME/.cargo/bin"
  displayName: Install rust - Unix
  condition: ne( variables['Agent.OS'], 'Windows_NT' )
  @@ -12,6 +13,7 @@ steps:
  - script: |
  curl -sSf -o rustup-init.exe https://win.rustup.rs
  rustup-init.exe -y --default-toolchain %TOOLCHAIN%
  + rustup update %TOOLCHAIN%
  echo "##vso[task.setvariable variable=PATH;]%PATH%;%USERPROFILE%\.cargo\bin"
  displayName: Install rust - Windows
  condition: eq( variables['Agent.OS'], 'Windows_NT' )
  