Fix up some stuff

proxy/src/main/java/com/velocitypowered/proxy/VelocityServer.java

@@ -246,7 +246,8 @@ public class VelocityServer implements ProxyServer {
       return false;
     }
 
-    // Re-register servers. If we are replacing a server, we must evacuate players.
+    // Re-register servers. If a server is being replaced, make sure to note what players need to
+    // move back to a fallback server.
     Collection<ConnectedPlayer> evacuate = new ArrayList<>();
     for (Map.Entry<String, String> entry : newConfiguration.getServers().entrySet()) {
       ServerInfo newInfo =
@@ -267,6 +268,8 @@ public class VelocityServer implements ProxyServer {
       }
     }
 
+    // If we had any players to evacuate, let's move them now. Wait until they are all moved off.
+    if (!evacuate.isEmpty()) {
       CountDownLatch latch = new CountDownLatch(evacuate.size());
       for (ConnectedPlayer player : evacuate) {
         Optional<RegisteredServer> next = player.getNextServerToTry();
@@ -291,6 +294,7 @@ public class VelocityServer implements ProxyServer {
         logger.error("Interrupted whilst moving players", e);
         Thread.currentThread().interrupt();
       }
+    }
 
     // If we have a new bind address, bind to it
     if (!configuration.getBind().equals(newConfiguration.getBind())) {