Release notes 0.12.3

Release notes 0.12.3:
-Correctly select music controller when coming back from the music controller menu
-Fixed a spot on the London map where zombies can't reach the player
-Fixed dead zombie bodies sometimes disappearing
-Fixed hell dogs not spawning in certain edge cases, mainly London map
-Fixed spinning towers not causing damage to zombies
-Fixed the player being blocked from moving forward straight away when unlocking barriers on the Military Map