title: gitflow-maven-plugin: Remote branch 'origin/master' is ahead of the local branch 'master'
body: <p>I use maven to create releases using gitflow-maven-plugin. My projects builds fine, unless I create a release calling the following maven command</p>
  
  <pre><code>mvn -B gitflow:release
  </code></pre>
  
  <p>This fails with the following error</p>
  
  <pre><code>[ERROR] Failed to execute goal com.amashchenko.maven.plugin:gitflow-maven-plugin:1.9.0:release (default-cli) on project test: 
  release: Remote branch 'origin/master' is ahead of the local branch 'master'. 
  Execute git pull. -&gt; [Help 1]
  </code></pre>
  
  <p>There are no changes on the master so there should be no such error, especially also cause the plugin does a fetch beforehand as shown in the log</p>
  
  <pre><code>16:03:21 [INFO] Fetching remote branch 'origin master'.
  16:03:21 [INFO] Comparing local branch 'master' with remote 'origin/master'
  </code></pre>
  
  <p>Any clue what could cause that?</p>