0.8.0 Release Candidate 2

Changes:

• Hopefully 🤞 fixing ingress for addon users
• Fixes for UI colors, etc
• Pin numpy to 1.19.4 for aarch64 but on Jetson Nano
• Ensure detection initializes at boot according to config when no mqtt value is retained
• Fix mqtt switch handling on restarts
• Ensure error message is printed when the config file is missing

Images:

• x86: blakeblackshear/frigate:0.8.0-rc2-amd64
• x86 w/ nvidia (for ffmpeg only): blakeblackshear/frigate:0.8.0-rc2-amd64nvidia
• Raspberry Pi 3/4 (32bit): blakeblackshear/frigate:0.8.0-rc2-armv7
• Raspberry Pi 4 (64bit): blakeblackshear/frigate:0.8.0-rc2-aarch64