Allow plugins to override Vanilla commands with aliases

Spigot broke this in 1.12, re-adding the logic back

Spigot-API-Patches/0060-Allow-plugins-to-override-Vanilla-commands-with-alia.patch

@@ -0,0 +1,23 @@
+From 0699a9e10e95f8f42a46728f02ac195d688515cd Mon Sep 17 00:00:00 2001
+From: Aikar <aikar@aikar.co>
+Date: Tue, 20 Jun 2017 18:58:35 -0400
+Subject: [PATCH] Allow plugins to override Vanilla commands with aliases
+
+Spigot broke this in 1.12, re-adding the logic back
+
+diff --git a/src/main/java/org/bukkit/command/SimpleCommandMap.java b/src/main/java/org/bukkit/command/SimpleCommandMap.java
+index 6f733fe0..ac3d5035 100644
+--- a/src/main/java/org/bukkit/command/SimpleCommandMap.java
++++ b/src/main/java/org/bukkit/command/SimpleCommandMap.java
+@@ -99,7 +99,7 @@ public class SimpleCommandMap implements CommandMap {
+      */
+     private synchronized boolean register(String label, Command command, boolean isAlias, String fallbackPrefix) {
+         knownCommands.put(fallbackPrefix + ":" + label, command);
+-        if (isAlias && knownCommands.containsKey(label)) {
++        if (("minecraft".equals(fallbackPrefix) || isAlias) && knownCommands.containsKey(label)) { // Paper - allow plugins to override vanilla commands as aliases
+             // Request is for an alias/fallback command and it conflicts with
+             // a existing command or previous alias ignore it
+             // Note: This will mean it gets removed from the commands list of active aliases
+-- 
+2.13.0
+