Do not send empty upsert player info packets

There is no harm in this, but seemingly, some common mod blows up on this, and,
well, why eat buffer?

proxy/src/main/java/com/velocitypowered/proxy/tablist/VelocityTabList.java

@@ -166,8 +166,10 @@ public class VelocityTabList implements InternalTabList {
       return entry;
     });
 
+    if (!actions.isEmpty()) {
       this.connection.write(new UpsertPlayerInfoPacket(actions, List.of(playerInfoEntry)));
     }
+  }
 
   @Override
   public Optional<TabListEntry> removeEntry(UUID uuid) {