Update netty to 4.1.50-final (neo4j#705)

Author: gjmwoods

pom.xml

@@ -64,7 +64,7 @@
       <dependency>
         <groupId>io.netty</groupId>
         <artifactId>netty-handler</artifactId>
-        <version>4.1.45.Final</version>
+        <version>4.1.50.Final</version>
       </dependency>
       <dependency>
         <groupId>io.projectreactor</groupId>