dev: fix Caddyfile and change watching for Linux
Created by: sqs
Both of these problems occurred on Linux for me, so I'm assuming they are Linux-specific. The first one (the Caddy port 80 one) really puzzles me about why nobody on macOS experienced it.
- fix https://github.com/sourcegraph/sourcegraph/issues/9536 using recommendation at https://github.com/caddyserver/caddy/issues/3219#issuecomment-608236439
- in dev watcher, react to precise-code-intel changes by restarting all
precise-code-intel-*
goreman procs instead of assuming it is a Go binary