Fix AsyncTabCompleteEvent not setting isCommand

Spigot-Server-Patches/AsyncTabCompleteEvent.patch

@@ -14,7 +14,7 @@ completion, such as offline players.
 Also adds isCommand and getLocation to the sync TabCompleteEvent
 
 diff --git a/src/main/java/net/minecraft/server/PlayerConnection.java b/src/main/java/net/minecraft/server/PlayerConnection.java
-index 5a620f3fd..35774f8bf 100644
+index 5a620f3fd..ead0994f8 100644
 --- a/src/main/java/net/minecraft/server/PlayerConnection.java
 +++ b/src/main/java/net/minecraft/server/PlayerConnection.java
 @@ -0,0 +0,0 @@ public class PlayerConnection implements PacketListenerPlayIn, ITickable {
@@ -41,7 +41,7 @@ index 5a620f3fd..35774f8bf 100644
 +        java.util.List<String> completions = new ArrayList<>();
 +        BlockPosition blockpos = packet.b();
 +        String buffer = packet.a();
-+        boolean isCommand = packet.c();
++        boolean isCommand = buffer.startsWith("/") || packet.c();
 +        event = new com.destroystokyo.paper.event.server.AsyncTabCompleteEvent(this.getPlayer(), completions,
 +            buffer, isCommand, blockpos != null ? MCUtil.toLocation(player.world, blockpos) : null);
 +        event.callEvent();