Update non-major netty dependencies to v4.2.1.Final

Author: renovate[bot]

gradle.properties

@@ -5,7 +5,7 @@ prevVersion=1.3.4
 #
 rxjava.version=2.2.21
 reactive-streams.version=1.0.4
-netty.version=4.1.119.Final
+netty.version=4.2.1.Final
 jctools.version=2.1.2
 annotations.version=26.0.2
 dagger.version=2.27