v86 emulator: Video color depth regressed (16 color, should be 32-bit)

Steps to reproduce:

• Go to emulator page: https://copy.sh/v86/
• At the bottom, select CD image: livecd.iso
• Set memory size: 512 MB
• Press "Start Emulation"

Once the system has entered the desktop mode, it's expected to have 32-bit color depth, however it's only 16 colors now. It seems bochsmp driver was not able to initialize, and then for some reason it performed fallback to vgasave.

	Before regression	After regression
Screenshot
Debug log	0.4.15-dev-5200-gac0a0ad.log	0.4.15-dev-5407-g79b0fce.log

The problem was found by Ben Nottelling in this commit which in turn was noticed by me. It started happening since bochsmp driver addition 0.4.15-dev-5201-ga337195 and still reproduced in 0.4.15-dev-5407-g79b0fce, so I'm attaching debug logs for the revision before regression and for current latest build.

hpoussin please look into this problem, tell me if some additional debugging needs to be enabled.