contrib/wix/help.wxs

color: add missing import of error

Found using Cython.

<?xml version="1.0" encoding="utf-8"?>
<Wix xmlns="http://schemas.microsoft.com/wix/2006/wi">

  <?include guids.wxi ?>
  <?include defines.wxi ?>

  <Fragment>
    <DirectoryRef Id="INSTALLDIR">
      <Directory Id="helpdir" Name="help" FileSource="$(var.SourceDir)">
        <Component Id="helpFolder" Guid="$(var.helpFolder.guid)" Win64='$(var.IsX64)'>
          <File Name="config.txt" KeyPath="yes" />
          <File Name="dates.txt" />
          <File Name="diffs.txt" />
          <File Name="environment.txt" />
          <File Name="extensions.txt" />
          <File Name="filesets.txt" />
          <File Name="glossary.txt" />
          <File Name="hgignore.txt" />
          <File Name="hgweb.txt" />
          <File Name="merge-tools.txt" />
          <File Name="multirevs.txt" />
          <File Name="patterns.txt" />
          <File Name="phases.txt" />
          <File Name="revisions.txt" />
          <File Name="revsets.txt" />
          <File Name="subrepos.txt" />
          <File Name="templates.txt" />
          <File Name="urls.txt" />
        </Component>
      </Directory>
    </DirectoryRef>
  </Fragment>

</Wix>