Updated log4j and Checker Framework

Updating Checker Framework flagged numerous warnings, which have been
corrected. These probably involve type declarations lacking a nullness
annotation that appeared elsewhere.

api/src/main/java/com/velocitypowered/api/event/query/ProxyQueryEvent.java

@@ -3,7 +3,6 @@ package com.velocitypowered.api.event.query;
 import com.google.common.base.Preconditions;
 import com.velocitypowered.api.proxy.server.QueryResponse;
 import java.net.InetAddress;
-import org.checkerframework.checker.nullness.qual.NonNull;
 
 /**
  * This event is fired if proxy is getting queried over GS4 Query protocol.
@@ -32,7 +31,6 @@ public final class ProxyQueryEvent {
    *
    * @return query type
    */
-  @NonNull
   public QueryType getQueryType() {
     return queryType;
   }
@@ -42,7 +40,6 @@ public final class ProxyQueryEvent {
    *
    * @return querier address
    */
-  @NonNull
   public InetAddress getQuerierAddress() {
     return querierAddress;
   }
@@ -52,7 +49,6 @@ public final class ProxyQueryEvent {
    *
    * @return the current query response
    */
-  @NonNull
   public QueryResponse getResponse() {
     return response;
   }
@@ -62,7 +58,7 @@ public final class ProxyQueryEvent {
    *
    * @param response the new non-null query response
    */
-  public void setResponse(@NonNull QueryResponse response) {
+  public void setResponse(QueryResponse response) {
     this.response = Preconditions.checkNotNull(response, "response");
   }
 

api/src/main/java/com/velocitypowered/api/plugin/meta/PluginDependency.java

@@ -14,8 +14,7 @@ import org.checkerframework.checker.nullness.qual.Nullable;
 public final class PluginDependency {
 
   private final String id;
-  @Nullable
-  private final String version;
+  private final @Nullable String version;
 
   private final boolean optional;
 

api/src/main/java/com/velocitypowered/api/proxy/server/QueryResponse.java

@@ -219,21 +219,11 @@ public final class QueryResponse {
    * A builder for {@link QueryResponse} objects.
    */
   public static final class Builder {
-
-    @MonotonicNonNull
-    private String hostname;
-
-    @MonotonicNonNull
-    private String gameVersion;
-
-    @MonotonicNonNull
-    private String map;
-
-    @MonotonicNonNull
-    private String proxyHost;
-
-    @MonotonicNonNull
-    private String proxyVersion;
+    private @MonotonicNonNull String hostname;
+    private @MonotonicNonNull String gameVersion;
+    private @MonotonicNonNull String map;
+    private @MonotonicNonNull String proxyHost;
+    private @MonotonicNonNull String proxyVersion;
 
     private int currentPlayers;
     private int maxPlayers;