Fix NPE sending resource pack without prompt

Fixes KyoriPowered/adventure#1075

patches/server/0010-Adventure.patch

@@ -4098,7 +4098,7 @@ index 55945b83a5426b352bad9507cc9e94afb1278032..9ea1537408ff2d790747b6e5a681d917
      public boolean isOp() {
          return true;
 diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
-index 654d4994bb2e65c5ca6b7190c15d2113eede9e5b..1c1f1db8cb8beff850103d998561d333823fe611 100644
+index 654d4994bb2e65c5ca6b7190c15d2113eede9e5b..4d1e8a9211462444543b4a16cefe369245e71b2f 100644
 --- a/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
 +++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftPlayer.java
 @@ -386,14 +386,40 @@ public class CraftPlayer extends CraftHumanEntity implements Player {
@@ -4317,7 +4317,7 @@ index 654d4994bb2e65c5ca6b7190c15d2113eede9e5b..1c1f1db8cb8beff850103d998561d333
 +        final Component prompt = io.papermc.paper.adventure.PaperAdventure.asVanilla(request.prompt());
 +        for (final java.util.Iterator<net.kyori.adventure.resource.ResourcePackInfo> iter = request.packs().iterator(); iter.hasNext();) {
 +            final net.kyori.adventure.resource.ResourcePackInfo pack = iter.next();
-+            packs.add(new ClientboundResourcePackPushPacket(pack.id(), pack.uri().toASCIIString(), pack.hash(), request.required(), iter.hasNext() ? Optional.empty() : Optional.of(prompt)));
++            packs.add(new ClientboundResourcePackPushPacket(pack.id(), pack.uri().toASCIIString(), pack.hash(), request.required(), iter.hasNext() ? Optional.empty() : Optional.ofNullable(prompt)));
 +            if (request.callback() != net.kyori.adventure.resource.ResourcePackCallback.noOp()) {
 +                this.getHandle().connection.packCallbacks.put(pack.id(), request.callback()); // just override if there is a previously existing callback
 +            }
@@ -5552,7 +5552,7 @@ index 64191fb2f238c6dacf894d88a703ced6e75a6054..cb6cc3896e862291a058d21fa9704dd1
  
          boolean hadFormat = false;
 diff --git a/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java b/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
-index 8a13d8ae4325854acb3be7083d022c08ba094df1..311b4472f955cba658afa763b2f0b31023b53236 100644
+index 951f76eff07e53af20105b29a4e3c81b78ef8b65..cac2bfc711daba11a640e4e776b10c86041b0670 100644
 --- a/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
 +++ b/src/main/java/org/bukkit/craftbukkit/util/CraftMagicNumbers.java
 @@ -80,6 +80,43 @@ public final class CraftMagicNumbers implements UnsafeValues {