tests: arrange for a server in wireproto-command-capabilities.t to be killed
The stray servers were piling up after the test harness exited. On Windows,
this means the *.pyd files can't be rebuilt, which is why the build warning
count dropped to 1 recently.
@echo off
powershell -NoProfile -ExecutionPolicy unrestricted -Command "& '%~dp0\editmergeps.ps1' %*"