Update Netty to 4.1.51

Minecraft's Netty version was severely out of date. There has been
numerous security fixes, bug fixes, and likely performance fixes
since the version Minecraft uses (4.1.25).

This fixes some known issues with "Closed Channel" spam.

Fixes #3388

Spigot-Server-Patches/0148-Use-TerminalConsoleAppender-for-console-improvements.patch

@@ -19,7 +19,7 @@ Other changes:
     configuration
 
 diff --git a/pom.xml b/pom.xml
-index adf32845001fae7a870f588184c2efaf0ab41504..d07ec94d3011eca8b986e45a63d0c6392691b273 100644
+index aec55b0b78fa47d427652d402cfbb61295672b11..48f5ed765cab101633efdcdd9118fd3cb5f97914 100644
 --- a/pom.xml
 +++ b/pom.xml
 @@ -44,10 +44,27 @@
@@ -54,7 +54,7 @@ index adf32845001fae7a870f588184c2efaf0ab41504..d07ec94d3011eca8b986e45a63d0c639
          </dependency>
          <dependency>
              <groupId>org.ow2.asm</groupId>
-@@ -252,10 +269,18 @@
+@@ -264,10 +281,18 @@
                                  <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
                                      <resource>META-INF/services/java.sql.Driver</resource>
                                  </transformer>