HADOOP-16982. Update Netty to 4.1.48.Final. Contributed by Lisheng Sun.

hadoop-project/pom.xml

@@ -787,7 +787,7 @@
       <dependency>
         <groupId>io.netty</groupId>
         <artifactId>netty-all</artifactId>
-        <version>4.1.45.Final</version>
+        <version>4.1.48.Final</version>
       </dependency>
 
       <dependency>