Fix dev server clientLogLevel

[jgierer12]

What kind of change does this PR introduce?

🐛 fix

Did you add tests for your changes?

N/A

Summary

In webpack-dev-server v3.4.0, the clientLogLevel value of none was removed and replaced with silent. As v3.4.0 falls in preact-cli's range of ^3.3.1, and webpack-dev-server strictly validates its options before starting, this should be causing preact watch to fail if the project was created after said dev server version was published.

See webpack/webpack-dev-server#1825

Does this PR introduce a breaking change?

No (other than bumping webpack-dev-server, which could be considered a breaking change, and probably should have on their part).

Other information

specs -m
Host: XPS 13 9370 
OS: Manjaro Linux x86_64 
Kernel: Linux 5.0.9-2-MANJARO 
CPU: Intel i7-8550U (8) @ 4.0GHz 
GPU: Intel UHD Graphics 620

node -v
v11.15.0

npm -v
6.9.0

yarn -v
1.16.0

[jgierer12]

This was already fixed in v3.4.1. I'll close this for now, it's probably better to just leave this at the now deprecated none for now.