Windows: Fix handler registration for development version of app
Windows: Fix handler registration for development version of app

Closes #497.

feross/webtorrent-app,feross/webtorrent-desktop,yciabaud/webtorrent-desktop,michaelgeorgeattard/webtorrent-desktop,webtorrent/webtorrent-desktop,webtorrent/webtorrent-desktop,yciabaud/webtorrent-desktop,feross/webtorrent-app,webtorrent/webtorrent-desktop,feross/webtorrent-app,yciabaud/webtorrent-desktop,michaelgeorgeattard/webtorrent-desktop,feross/webtorrent-desktop,michaelgeorgeattard/webtorrent-desktop,feross/webtorrent-desktop