Merge #1976

1976: fix spelling in  PULL_REQUEST_TEMPLATE.md r=mergify[bot] a=ghostwheel42

## What type of PR?

bug-fix

## What does this PR do?

fix spelling in  PULL_REQUEST_TEMPLATE.md => Prerequisites

## Prerequisites
Before we can consider review and merge, please make sure the following list is done and checked.
If an entry in not applicable, you can check it or remove it from the list.

- [X] In case of feature or enhancement: documentation updated accordingly
- [X] Unless it's docs or a minor change: add [changelog](https://mailu.io/master/contributors/workflow.html#changelog) entry file.


Co-authored-by: Alexander Graf <ghostwheel42@users.noreply.github.com>

PULL_REQUEST_TEMPLATE.md

@@ -8,7 +8,7 @@
 - Mention an issue like: #001
 - Auto close an issue like: closes #001
 
-## Prerequistes
+## Prerequisites
 Before we can consider review and merge, please make sure the following list is done and checked.
 If an entry in not applicable, you can check it or remove it from the list.