mediawiki.log: Remove call to console.trace() for each warning
When code that accesses a deprecated property is called multiple times,
every time a deprecation message is logged and a stack trace produced.
And all synchronously as well. This creates a duplicative mess in the
While less convenient, there are other ways to get the calling
function from a warning (e.g. debugger, breakpoints, pause/step
execution). We don't call it for mw.log.error, either.
This should help reduce noise, speed up execution path, and hopefully
prevent such crashes in the future.