Log Message:
databases/ruby-activeldap: update to 6.0.1

Update ruby-activeldap to 6.0.1.

## 6.0.1: 2020-04-21 {#release-6-0-1}

### Improvements

  * Dropped support for Ruby 2.4.

  * Stopped using paged results when we need only one entry.
    [GitHub#173][Patch by Kevin McCormack]

### Thanks

  * Kevin McCormack

## 6.0.0: 2020-04-16 {#release-6-0-0}

### Improvements

  * Removed needless `rubyforge_project` from `.gemspec`.
    [GitHub#167][Patch by Olle Jonsson]

  * Added support for reusing parent configuration for omitted
    configuration items when creating a connection per class or DN.

  * jndi: Added support for processing DN that includes backslash.

  * jndi: Added a CI job for JRuby 9.
    [GitHub#170][Patch by Kevin McCormack]

  * jndi: Added support for paged search.
    [GitHub#171][Patch by Kevin McCormack]

  * Added support for Active Model 6.

  * `search`: Added `:used_paged_results` and `:page_size` options.

### Thanks

  * Olle Jonsson

  * Kevin McCormack