mac build: add message to camera permission prompt, in Info.plist
mac build: add message to camera permission prompt, in Info.plist

based on https://github.com/Electron-Cash/Electron-Cash/commit/0b5b5fb228dbd3be60197b7ccde27ff32d9786ad

Co-authored-by: Calin Culianu <57549f2037ccc250f2203dbfbed8f6f454d58f12@gmail.com>

spesmilo/electrum,pooler/electrum-ltc,spesmilo/electrum,spesmilo/electrum,pooler/electrum-ltc,pooler/electrum-ltc,pooler/electrum-ltc,spesmilo/electrum