GH-719: Exclude Spring 4.X dependency

Fixes #719

Exclusion of Spring 4.X transitive dependencies from Spring-Retry

**Cherry-pick to 2.1.x and 2.0.x**

Author: fabienmifsud

build.gradle

@@ -189,7 +189,9 @@ project ('spring-kafka') {
 		compile "org.springframework:spring-context:$springVersion"
 		compile "org.springframework:spring-messaging:$springVersion"
 		compile "org.springframework:spring-tx:$springVersion"
-		compile "org.springframework.retry:spring-retry:$springRetryVersion"
+		compile ("org.springframework.retry:spring-retry:$springRetryVersion") {
+			exclude group: 'org.springframework', module: 'spring-core'
+		}
 		compile "org.apache.kafka:kafka-clients:$kafkaVersion"
 		compile ("org.apache.kafka:kafka-streams:$kafkaVersion", optional)