Incorrect reference to `__hmac`

[ohader]

https://docs.typo3.org/other/typo3/view-helper-reference/main/en-us/Global/Form/Index.html#security-in-fluid-forms

The reference to __hmac seems to be incorrect. Probably __trustedProperties is meant here (which contains an HMAC as cryptographic signature).

---

Example output of f:form (used in Extbase context):

<form action="/admin/module/system/user-management/BackendUser/list?token=328190ab378fe49af07d8b6b4ec31f87bd910efc" method="post">
<div>
<input type="hidden" name="__referrer[@extension]" value="Beuser">
<input type="hidden" name="__referrer[@controller]" value="BackendUser">
<input type="hidden" name="__referrer[@action]" value="list">
<input type="hidden" name="__referrer[arguments]" value="YTozOntzOjEwOiJjb250cm9sbGVyIjtzOjExOiJCYWNrZW5kVXNlciI7czo2OiJhY3Rpb24iO3M6NToiaW5kZXgiO3M6NToidG9rZW4iO3M6NDA6IjgxNWZhOGI0OGYyZDg0N2NkMzcwYWIzYTkyMjhlNDY2OWI4OTI0MmUiO30=b305f0773528375502f167cde7c6c63f6ba988f8">
<input type="hidden" name="__referrer[@request]" value="{&quot;@extension&quot;:&quot;Beuser&quot;,&quot;@controller&quot;:&quot;BackendUser&quot;,&quot;@action&quot;:&quot;list&quot;}51b024523b594011fa9054f7fc82c03ead78061a">
<input type="hidden" name="__trustedProperties" value="{&quot;demand&quot;:{&quot;userName&quot;:1,&quot;userType&quot;:1,&quot;status&quot;:1,&quot;logins&quot;:1,&quot;backendUserGroup&quot;:1},&quot;operation&quot;:1}c25fc9eb44fc0e40e8ec5cf39fc5d21022172ebe">
</div>

• __referrer[arguments] has appended HMAC
• __referrer[@request] has appended HMAC
• __trustedProperties has appended HMAC

[garvinhicking]

Would #116 be ok for you?