Revert "HDFS-16384. Upgrade Netty to 4.1.72.Final (#3798)"

This reverts commit a4557f9ed9.

LICENSE-binary

@@ -261,7 +261,7 @@ io.grpc:grpc-protobuf:1.26.0
 io.grpc:grpc-protobuf-lite:1.26.0
 io.grpc:grpc-stub:1.26.0
 io.netty:netty:3.10.6.Final
-io.netty:netty-all:4.1.72.Final
+io.netty:netty-all:4.1.42.Final
 io.netty:netty-buffer:4.1.27.Final
 io.netty:netty-codec:4.1.27.Final
 io.netty:netty-codec-http:4.1.27.Final

hadoop-hdfs-project/hadoop-hdfs-client/pom.xml

@@ -85,10 +85,6 @@ https://maven.apache.org/xsd/maven-4.0.0.xsd">
           <groupId>io.netty</groupId>
           <artifactId>netty-codec-http</artifactId>
         </exclusion>
-        <exclusion>
-          <groupId>io.netty</groupId>
-          <artifactId>netty-codec-socks</artifactId>
-        </exclusion>
         <exclusion>
           <groupId>io.netty</groupId>
           <artifactId>netty-common</artifactId>
@@ -97,10 +93,6 @@ https://maven.apache.org/xsd/maven-4.0.0.xsd">
           <groupId>io.netty</groupId>
           <artifactId>netty-handler</artifactId>
         </exclusion>
-        <exclusion>
-          <groupId>io.netty</groupId>
-          <artifactId>netty-handler-proxy</artifactId>
-        </exclusion>
         <exclusion>
           <groupId>io.netty</groupId>
           <artifactId>netty-transport</artifactId>

hadoop-project/pom.xml

@@ -141,7 +141,7 @@
     <gson.version>2.2.4</gson.version>
     <metrics.version>3.2.4</metrics.version>
     <netty3.version>3.10.6.Final</netty3.version>
-    <netty4.version>4.1.72.Final</netty4.version>
+    <netty4.version>4.1.68.Final</netty4.version>
     <snappy-java.version>1.1.8.2</snappy-java.version>
     <lz4-java.version>1.7.1</lz4-java.version>