Include shaded netty-all in hbase-shaded-mapreduce

Since ZooKeeper TLS connection is supported within HBase, we need netty-all on the classpath. It's already present in hbase-shaded-client and we need it in hbase-shaded-mapreduce for MR clients too. netty-all is already included in pom.xml, but only with test-scope, so shading plugin doesn't add it to the jar. Patch will override it to compile-scope.