0.2.6.1 small update

A new setting for missile seeker efficiency has been added to the game settings. The higher the seeker efficiency, the more sensitive the missile will track the target (both you and your enemies!) Players' Aircraft is able to respawn when playing campaign. In easy level, you have 2 respawn opportunities. In normal level, you can respawn only once after being shot down. In hard level, you cannot respawn after being shot down Fixed a bug that allowed the aircraft to fire after being destroyed