Reindent some chunks of code

It bothered me the fact that some chunks of code are indented like this:

```ruby
  def some_method
    # ...
  end

  private

  def some_other_method
    # ...
  end
```

and some others like this:

```ruby
  def some_method
    # ...
  end

private
  def some_other_method
    # ...
  end
```

and others like this:

```ruby
def some_method
    # ...
  end

private
def some_other_method
  # ...
end
```

So I've modified those chunks of code that looks like the second and third style to look like the first one.