title: Prevent PhpStorm from adding “Signed-off-by: …” at the end of commit message
body: <p>When I create a commit with <code>git</code> using command line, the commit message is not altered.</p>
  
  <p>When I create a commit though PhpStorm's GUI with the checkbox “Sign-off commit” checked, PhpStorm add this line at the end of my commit message:</p>
  
  <pre><code>Signed-off-by: Firstname Lastname &lt;me@example.com&gt;
  </code></pre>
  
  <p>How to prevent this? I don't want PhpStorm to write “Signed-off-by: …” at the end of every commit.</p>
  
  <hr>
  
  <p>Here is my git configuration:</p>
  
  <pre><code>$ git config --list
  commit.gpgsign=false
  user.signingkey=…
  user.name=Firstname Lastname
  user.email=me@example.com
  push.default=current
  core.excludesfile=/home/…/.gitignore_global
  fetch.prune=true
  rebase.autosquash=true
  gpg.program=gpg2
  format.signoff=false
  core.repositoryformatversion=0
  core.filemode=true
  core.bare=false
  core.logallrefupdates=true
  remote.origin.url=git@github.com:Victoire/victoire.git
  remote.origin.fetch=+refs/heads/*:refs/remotes/origin/*
  commit.gpgsign=true
  </code></pre>