devserver: Stop patching devserver internals for port=0

Newer cherrypy understands that a port=0 means picking up a random
port. So we don't need this manual hacking anymore. Besides, I don't
think we normally start devserver that way anyway. The default port is
8080 and nobody is passing --port=0 to the devserver.py.

BUG=chromium:1015973
TEST=`./devserver_integration_test.py` with cherrypy 17.4.1-r1
TEST=./cherrypy_ext_unittest.py

Cq-Depend: chromium:1872628
Change-Id: Icb7c26235c0dbb334a42dbd14dc3a015d67b2001
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/1871764
Tested-by: Amin Hassani <[email protected]>
Reviewed-by: Mike Frysinger <[email protected]>
Commit-Queue: Mike Frysinger <[email protected]>
3 files changed