Remove freenode badges, Add link to Talk

Signed-off-by: Daniel Kesselberg <mail@danielkesselberg.de>

README.md

@@ -2,8 +2,6 @@
 [![Scrutinizer Code Quality](https://scrutinizer-ci.com/g/nextcloud/server/badges/quality-score.png?b=master)](https://scrutinizer-ci.com/g/nextcloud/server/?branch=master)
 [![codecov](https://codecov.io/gh/nextcloud/server/branch/master/graph/badge.svg)](https://codecov.io/gh/nextcloud/server)
 [![CII Best Practices](https://bestpractices.coreinfrastructure.org/projects/209/badge)](https://bestpractices.coreinfrastructure.org/projects/209)
-[![irc](https://img.shields.io/badge/IRC-%23nextcloud%20on%20freenode-orange.svg)](https://webchat.freenode.net/?channels=nextcloud)
-[![irc](https://img.shields.io/badge/IRC-%23nextcloud--dev%20on%20freenode-blue.svg)](https://webchat.freenode.net/?channels=nextcloud-dev)
 
 **A safe home for all your data.**