Set upper bound of netty version (#2482)

A new alpha version is introduced and breaks our tests.

dependencies.gradle

@@ -56,13 +56,14 @@ ext {
       'org.hibernate:hibernate-core:[5.6.14.Final, 6.0)',
       'org.hibernate:hibernate-hikaricp:[5.6.14.Final, 6.0)',
 
-      // Netty 5.0 is in alpha and breaks API.
-      'io.netty:netty-codec-http:[4.1.59.Final, 5.0.0)!!',
-      'io.netty:netty-codec:[4.1.59.Final, 5.0.0)!!',
-      'io.netty:netty-common:[4.1.59.Final, 5.0.0)!!',
-      'io.netty:netty-handler:[4.1.59.Final, 5.0.0)!!',
-      'io.netty:netty-transport:[4.1.59.Final, 5.0.0)!!',
-      'io.netty:netty-buffer:[4.1.59.Final, 5.0.0)!!',
+      // Netty 4.2 is in alpha and causes runtime error. Also note that v5.0
+      // seems abandoned (last updated on Maven in 2015).
+      'io.netty:netty-codec-http:[4.1.59.Final, 4.2.0)!!',
+      'io.netty:netty-codec:[4.1.59.Final, 4.2.0)!!',
+      'io.netty:netty-common:[4.1.59.Final, 4.2.0)!!',
+      'io.netty:netty-handler:[4.1.59.Final, 4.2.0)!!',
+      'io.netty:netty-transport:[4.1.59.Final, 4.2.0)!!',
+      'io.netty:netty-buffer:[4.1.59.Final, 4.2.0)!!',
 
       // OkHttp 5.0 is in alpha.
       'com.squareup.okhttp3:okhttp:[4.10.0, 5.0.0)!!',