Bump netty-all in /flink-connector-netty to 4.1.42.Final (#67)

Bumps [netty-all](https://github.com/netty/netty) from 4.1.5.Final to 4.1.42.Final.
- [Release notes](https://github.com/netty/netty/releases)
- [Commits](https://github.com/netty/netty/compare/netty-4.1.5.Final...netty-4.1.42.Final)

Signed-off-by: dependabot[bot] <support@github.com>
diff --git a/flink-connector-netty/pom.xml b/flink-connector-netty/pom.xml
index 634b24f..76c8934 100644
--- a/flink-connector-netty/pom.xml
+++ b/flink-connector-netty/pom.xml
@@ -34,7 +34,7 @@
     <dependency>
       <groupId>io.netty</groupId>
       <artifactId>netty-all</artifactId>
-      <version>4.1.5.Final</version>
+      <version>4.1.42.Final</version>
     </dependency>
     <dependency>
       <groupId>org.apache.flink</groupId>