Fix keepalive logic resetting counter

This would of actually arised in the client being kicked due to sending
bad keepalive packets due to the erronious extra sending of keepalives too

paper-server/patches/sources/net/minecraft/server/network/ServerCommonPacketListenerImpl.java.patch

@@ -95,7 +95,7 @@
          }
      }
 
-@@ -88,30 +_,117 @@
+@@ -88,30 +_,119 @@
      public void handlePong(ServerboundPongPacket packet) {
      }
 
@@ -208,15 +208,16 @@
          Profiler.get().push("keepAlive");
          long millis = Util.getMillis();
 -        if (!this.isSingleplayerOwner() && millis - this.keepAliveTime >= 15000L) {
--            if (this.keepAlivePending) {
--                this.disconnect(TIMEOUT_DISCONNECTION_MESSAGE);
 +        // Paper start - give clients a longer time to respond to pings as per pre 1.12.2 timings
 +        // This should effectively place the keepalive handling back to "as it was" before 1.12.2
 +        final long elapsedTime = millis - this.keepAliveTime;
 +        if (!this.isSingleplayerOwner() && elapsedTime >= 15000L) { // use vanilla's 15000L between keep alive packets
-+            if (this.keepAlivePending && !this.processedDisconnect && elapsedTime >= KEEPALIVE_LIMIT) { // check keepalive limit, don't fire if already disconnected
+             if (this.keepAlivePending) {
+-                this.disconnect(TIMEOUT_DISCONNECTION_MESSAGE);
++                if (!this.processedDisconnect && elapsedTime >= KEEPALIVE_LIMIT) { // check keepalive limit, don't fire if already disconnected
++                    this.disconnect(TIMEOUT_DISCONNECTION_MESSAGE, org.bukkit.event.player.PlayerKickEvent.Cause.TIMEOUT); // Paper - kick event cause
++                }
 +                // Paper end - give clients a longer time to respond to pings as per pre 1.12.2 timings
-+                this.disconnect(TIMEOUT_DISCONNECTION_MESSAGE, org.bukkit.event.player.PlayerKickEvent.Cause.TIMEOUT); // Paper - kick event cause
              } else if (this.checkIfClosed(millis)) {
                  this.keepAlivePending = true;
                  this.keepAliveTime = millis;