mina sets every command run(:local) to :local when if run(:remote) was not explicitly called

[Jayden Ma]

I notice that when even thou the documentation states that the default is backend is set to :remote,
it does not explicitly do so and this causes all commands before the run(:local) to run in :local which is
the wrong environment.
Probably due to run(:local) setting the @backend to :local

eg.

in deploy.rb

task :setup do
  invoke :'nginx:setup'
  run(:local) do
    invoke :'setup_rails_env'
  end
end

will cause nginx:setup to run in :local

task :setup do
  run(:remote) do
    invoke :'nginx:setup'
  end
  run(:local) do
    invoke :'setup_rails_env'
  end
end

will make sure nginx:setup is is run in :remote

task :setup do
  run(:remote) do
    # something else
  end
  invoke :'nginx:setup'
  run(:local) do
    invoke :'setup_rails_env'
  end
end

that something else will run in :remote while nginx:setup runs in local