Restore the default airdrop spawns when unloading plugin

Fix for new unturned update

Add mass airdrop grenade suggested by Darkways

Fix automatic generation of Rio de Janeiro airdrop spawns and set the storage of custom airdrops in Airdrops.xml

Downgrade harmony from 2.3.3 to 2.2.2

Fix escalation midnight boss error

Log airdrop interval logs only when there is at least 1 player on the server

add missing {min_players} variable

upload airdrop manager 3 files