Bump Netty to 4.1.49.Final

This is intended to fix netty/netty#10165 directly, and supersede our current workaround.

build.gradle

@@ -24,7 +24,7 @@ allprojects {
         junitVersion = '5.3.0-M1'
         slf4jVersion = '1.7.25'
         log4jVersion = '2.11.2'
-        nettyVersion = '4.1.37.Final'
+        nettyVersion = '4.1.49.Final'
         guavaVersion = '25.1-jre'
         checkerFrameworkVersion = '2.7.0'