Icon replaced by Material Symbol

Signed-off-by: Andy Scherzinger <info@andy-scherzinger.de>

README.md

@@ -18,7 +18,3 @@ The *Teams* app is installed and enabled by default.
 
 # Documentation
 You can use the `\Psr\Container\ContainerInterface`, see [dependency injection](https://docs.nextcloud.com/server/stable/developer_manual/basics/dependency_injection.html), to get the `\OCA\Circles\CireclesManager` class, see our [API documentation](https://nextcloud.github.io/circles/) for its interface.
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-### Credits
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-App Icon by [Madebyoliver](http://www.flaticon.com/authors/madebyoliver) under Creative Commons BY 3.0