Upgrade to Netty 4.1.42 (elastic#48015)

Upgrades the netty version.

Author: Tim-Brooks

buildSrc/version.properties

@@ -21,7 +21,7 @@ slf4j             = 1.6.2
 # when updating the JNA version, also update the version in buildSrc/build.gradle
 jna               = 4.5.1
 
-netty             = 4.1.38.Final
+netty             = 4.1.42.Final
 joda              = 2.10.3
 
 # when updating this version, you need to ensure compatibility with:

modules/transport-netty4/licenses/netty-buffer-4.1.38.Final.jar.sha1

@@ -0,0 +1 @@
+6e6fc9178d1f1401aa0d6b843341efb91720f2cd

modules/transport-netty4/licenses/netty-buffer-4.1.42.Final.jar.sha1

@@ -0,0 +1 @@
+b1d5ed85a558fbbadc2783f869fbd0adcd32b07b

modules/transport-netty4/licenses/netty-codec-4.1.38.Final.jar.sha1

@@ -0,0 +1 @@
+5f71267aa784d0e6c5ec09fb988339d244b205a0

modules/transport-netty4/licenses/netty-codec-4.1.42.Final.jar.sha1

@@ -0,0 +1 @@
+e02700b574d3a0e2100308f971f0753ac8700e7c