title: git flow init -d default suggestions are empty
body: <p>I'm using Git flow on Windows. When I'm initializing my repo via</p>
  
  <pre><code>git flow init -d 
  </code></pre>
  
  <p>I get the following output</p>
  
  <pre><code>Which branch should be used for bringing forth production releases?
  - develop
  - master
   Branch name for production releases: [master]
  
  Which branch should be used for integration of the "next release"?
    - develop
  Branch name for "next release" development: [develop]
  
  How to name your supporting branch prefixes?
  Feature branches? []
  Bugfix branches? []
  Release branches? []
  Hotfix branches? []
  Support branches? []
  Version tag prefix? []
  </code></pre>
  
  <p>As can be seen, the default prefixes are empty. Can anyone tell me in which config file these prefixes are set?</p>
  
  <p>The problem is that I'm using a PowerShell script to clone multiple repos and init the repos via <code>git flow init -d</code>, so I need the default values.</p>
  
  <p>Thx</p>