Fix 2 kill button bugs (#7)

Co-authored-by: js6pak <kubastaron@hotmail.com>

Reactor/Patches/KillButtonPatches.cs

@@ -0,0 +1,33 @@
+using HarmonyLib;
+
+namespace Reactor.Patches
+{
+    /// <summary>
+    /// Fixes kill cooldown resetting for a few frames if anyone on the map got the kill
+    /// Also fixes invisible kill button if KillCooldown is set to 0
+    /// </summary>
+    internal class KillButtonPatches
+    {
+        [HarmonyPatch(typeof(PlayerControl), nameof(PlayerControl.SetKillTimer))]
+        [HarmonyPriority(Priority.First)]
+        public static class SetKillTimerPatch
+        {
+            public static bool Prefix(PlayerControl __instance, [HarmonyArgument(0)] float time)
+            {
+                __instance.killTimer = time;
+
+                // Patched because of this - game doesn't check if you're the killer
+                if (__instance.AmOwner)
+                {
+                    HudManager.Instance.KillButton.SetCoolDown(
+                        time,
+                        // if MaxTimer is 0, kill button disappears
+                        PlayerControl.GameOptions.KillCooldown <= 0 ? 1 : PlayerControl.GameOptions.KillCooldown
+                    );
+                }
+
+                return false;
+            }
+        }
+    }
+}