Bug 845134 - Modify annotation to skip test_focusedChild.html on Windows 10; r=me,test-only

accessible/tests/mochitest/focus/a11y.ini

@@ -3,7 +3,7 @@ support-files =
   !/accessible/tests/mochitest/*.js
 
 [test_focusedChild.html]
-skip-if = (os == 'win' && (os_version == '6.2' || os_version == '6.3' || os_version == '10.0.15063')) # bug 845134
+skip-if = (os == 'win' && os_version != '6.1') # bug 845134
 [test_takeFocus.html]
 skip-if = buildapp == 'mulet'
 [test_takeFocus.xul]