Skip editor orphaned test on windows.

Tried SIGINT/SIGTERM, neither worked. Just skip this test on windows and
go back to SIGUSR1 otherwise.

tests/end2end/features/editor.feature

@@ -115,6 +115,8 @@ Feature: Opening external editors
         And I run :click-element id qute-button
         Then the javascript message "text: foobar" should be logged
 
+    # Could not get signals working on Windows
+    @posix
     Scenario: Spawning an editor and closing the tab
         When I set up a fake editor that waits
         And I open data/editor.html

tests/end2end/features/test_editor_bdd.py

@@ -82,12 +82,8 @@ def set_up_editor_wait(quteproc, server, tmpdir):
         with open(r'{pidfile}', 'w') as f:
             f.write(str(os.getpid()))
 
-        signal.signal(signal.SIGINT, lambda s, f: sys.exit(0))
-
-        try:
-            time.sleep(100)
-        except InterruptedError:
-            pass
+        signal.signal(signal.SIGUSR1, lambda s, f: sys.exit(0))
+        time.sleep(100)
     """.format(pidfile=pidfile)))
     editor = json.dumps([sys.executable, str(script), '{}'])
     quteproc.set_setting('editor.command', editor)
@@ -98,4 +94,4 @@ def kill_editor_wait(quteproc, server, tmpdir):
     """Kill the waiting editor."""
     pidfile = tmpdir / 'editor_pid'
     pid = int(pidfile.read())
-    os.kill(pid, signal.SIGINT)
+    os.kill(pid, signal.SIGUSR1)