Fixes https://github.com/spring-projects/spring-integration/issues/2974 There is a race in that we could get a `SocketException` in `inputStream`. Since this is between payloads, it needs to be thrown as a `SoftEndOfStreamException`. Also fix unnecessary `this.` in `MessageHistoryConfigurer.java`. **cherry-pick to 5.0.x, 4.3.x** * * Add javadocs to SoftEndOfStreamException