Remove links to gitter.

Closes: #3808

Author: christophstrobl

README.adoc

@@ -1,4 +1,4 @@
-= Spring Data JPA image:https://jenkins.spring.io/buildStatus/icon?job=spring-data-jpa%2Fmain&subject=Build[link=https://jenkins.spring.io/view/SpringData/job/spring-data-jpa/] https://gitter.im/spring-projects/spring-data[image:https://badges.gitter.im/spring-projects/spring-data.svg[Gitter]] image:https://img.shields.io/badge/Revved%20up%20by-Develocity-06A0CE?logo=Gradle&labelColor=02303A["Revved up by Develocity", link="https://ge.spring.io/scans?search.rootProjectNames=Spring Data JPA Parent"]
+= Spring Data JPA image:https://jenkins.spring.io/buildStatus/icon?job=spring-data-jpa%2Fmain&subject=Build[link=https://jenkins.spring.io/view/SpringData/job/spring-data-jpa/] image:https://img.shields.io/badge/Revved%20up%20by-Develocity-06A0CE?logo=Gradle&labelColor=02303A["Revved up by Develocity", link="https://ge.spring.io/scans?search.rootProjectNames=Spring Data JPA Parent"]
 
 Spring Data JPA, part of the larger https://projects.spring.io/spring-data[Spring Data] family, makes it easy to implement JPA-based repositories.
 This module deals with enhanced support for JPA-based data access layers.
@@ -132,7 +132,6 @@ https://docs.spring.io/spring-data/jpa/reference/[reference documentation], and
 If you are just starting out with Spring, try one of the https://spring.io/guides[guides].
 * If you are upgrading, check out the https://github.com/spring-projects/spring-data-jpa/releases[Spring Data JPA release notes] and scroll down to the one you're considering. See the details there. (Also check out the https://github.com/spring-projects/spring-data-jpa/releases/latest[latest stable release])
 * Ask a question - we monitor https://stackoverflow.com[stackoverflow.com] for questions tagged with https://stackoverflow.com/tags/spring-data[`spring-data-jpa`].
-You can also chat with the community on https://gitter.im/spring-projects/spring-data[Gitter].
 * Report bugs with Spring Data JPA in the https://github.com/spring-projects/spring-data-jpa/issues[GitHub issue tracker].
 
 == Reporting Issues