**Steps to replicate the issue** (include links if applicable):
* Open any page in the main namespace of nl.wiktionary using the legacy Vector skin, e.g. [proscriptie](https://nl.wiktionary.org/wiki/proscriptie?useskin=vector)
**What happens?**:
* The TOC shows headers in the form
`<i>header text</i>
`. Screenshot:
{F66738898}
**Additional information**
* nl.wiktionary uses headings that are in italics, using templates with
''`''` in wikitext.
* the heading created by our template
`{{-pron-}}
is` is:
```
lang=html
<div class="mw-heading mw-heading5" id="mwRA"><h5 about="#mwt2" typeof="mw:Transclusion" id="Uitspraak" data-mw="{"parts":[{"template":{"target":{"wt":"-pron-","href":"./Sjabloon:-pron-"},"params":{},"i":0}}]}"><i><a rel="mw:WikiLink" href="//nl.wiktionary.org/wiki/WikiWoordenboek:Uitspraak" title="WikiWoordenboek:Uitspraak">Uitspraak</a></i></h5></div>
```
* but in de TOC it is rendered as
`<i>Uitspraak</i>
`
* This bug was reported this morning by a user usually contributing every day. I myself use the new Vector skin, but I was able to reproduce the error when using the old skin.
**What should have happened instead?**:
* The items in TOC should be shown in italics, without tags
**Software version** (on `Special:Version` page; skip for WMF-hosted wikis like Wikipedia):
**Other information** (browser name/version, screenshots, etc.):
* The bug is visible in Firefox and Chrome.