title: Unescaped left brace regex error
body: <p>I’m not an expert in regex and can't figure what I am supposed to change here.</p>
  
  <p>I get these two errors</p>
  
  <p>Unescaped left brace in regex is deprecated, passed through in regex; marked by <code>&lt;-- HERE</code> in <code>m/^(.*?)(\\)?\${ &lt;-- HERE ([^{}]+)}(.*)$/</code> at /usr/share/perl5/Debconf/Question.pm line 72.</p>
  
  <p>Unescaped left brace in regex is deprecated, passed through in regex; marked by <code>&lt;-- HERE</code> in <code>m/\${ &lt;-- HERE ([^}]+)}/</code> at /usr/share/perl5/Debconf/Config.pm line 30.</p>
  
  <p>When I jump to the line 72 this is what I see</p>
  
  <pre><code>while ($rest =~ m/^(.*?)(\\)?\${([^{}]+)}(.*)$/sg) {
  </code></pre>