Fix compile error caused by adventure changes

api/src/main/java/com/velocitypowered/api/event/ResultedEvent.java

@@ -108,7 +108,7 @@ public interface ResultedEvent<R extends ResultedEvent.Result> {
         return "allowed";
       }
       if (reason != null) {
-        return "denied: " + PlainComponentSerializer.INSTANCE.serialize(reason);
+        return "denied: " + PlainComponentSerializer.plain().serialize(reason);
       }
       return "denied";
     }

proxy/src/main/java/com/velocitypowered/proxy/protocol/netty/GS4QueryHandler.java

@@ -72,7 +72,7 @@ public class GS4QueryHandler extends SimpleChannelInboundHandler<DatagramPacket>
 
   private QueryResponse createInitialResponse() {
     return QueryResponse.builder()
-        .hostname(PlainComponentSerializer.INSTANCE.serialize(server.getConfiguration().getMotd()))
+        .hostname(PlainComponentSerializer.plain().serialize(server.getConfiguration().getMotd()))
         .gameVersion(ProtocolVersion.SUPPORTED_VERSION_STRING)
         .map(server.getConfiguration().getQueryMap())
         .currentPlayers(server.getPlayerCount())

proxy/src/main/java/com/velocitypowered/proxy/protocol/packet/LegacyDisconnect.java

@@ -12,7 +12,8 @@ public class LegacyDisconnect {
 
   private static final ServerPing.Players FAKE_PLAYERS = new ServerPing.Players(0, 0,
       ImmutableList.of());
-  private static final String LEGACY_COLOR_CODE = "\u00a7";
+  private static final String LEGACY_COLOR_CODE = Character
+      .toString(LegacyComponentSerializer.SECTION_CHAR);
 
   private final String reason;
 
@@ -36,7 +37,7 @@ public class LegacyDisconnect {
         // remove all section symbols, along with fetching just the first line of an (unformatted)
         // MOTD.
         return new LegacyDisconnect(String.join(LEGACY_COLOR_CODE,
-            cleanSectionSymbol(getFirstLine(PlainComponentSerializer.INSTANCE.serialize(
+            cleanSectionSymbol(getFirstLine(PlainComponentSerializer.plain().serialize(
                 response.getDescriptionComponent()))),
             Integer.toString(players.getOnline()),
             Integer.toString(players.getMax())));