Upgrade Netty (#1694)

It is including 2 security fixes:

* https://snyk.io/vuln/SNYK-JAVA-IONETTY-543669
* https://snyk.io/vuln/SNYK-JAVA-IONETTY-543490

Author: aheritier

pom.xml

@@ -447,7 +447,7 @@
     <surefire.redirectTestOutputToFile>true</surefire.redirectTestOutputToFile>
     <source.property>1.8</source.property>
     <target.property>1.8</target.property>
-    <netty.version>4.1.42.Final</netty.version>
+    <netty.version>4.1.44.Final</netty.version>
     <slf4j.version>1.7.26</slf4j.version>
     <reactive-streams.version>1.0.2</reactive-streams.version>
     <activation.version>1.2.0</activation.version>