…3230)

This reverts commit 5334d1a
karma-webpack preprocessor updates bundle when needed, but karma's fileList consists of a single entry file which is usually unmodified. In this case, fileList.refresh() should always call preprocessor for the single entry file, avoiding preprocessing of unmodified files is done on karma-webpack side.

* fix: restarted browsers not running tests

Currently whenever a browser disconnects completely (no socket.io connection loss), the launcher is instructed to "restart" the browser. Whenever the restarted browser now tries to "register" again, Karma considers the browser instance to be still executing and doesn't do anything about it (except setting the state to `EXECUTING` again).

This means that the browser is in the state of executing, but
practically it does nothing just waits. Resulting another disconnect
(repeat here).

* test: add unit test that covers disconnected restarted browsers

* fixup! test: add unit test that covers disconnected restarted browsers

Address feedback

* fixup! test: add unit test that covers disconnected restarted browsers

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