Bug 814749 - Disable test_248970.js in per-window PB builds; r=ehsan

--HG--
extra : rebase_source : 8c19f0754799aea9326d7a42caac4e0511d0546b

toolkit/components/places/tests/unit/xpcshell.ini

@@ -1,9 +1,10 @@
 [DEFAULT]
 head = head_bookmarks.js
-tail = 
+tail =
 
 [test_000_frecency.js]
 [test_248970.js]
+skip-if = perwindowprivatebrowsing
 [test_317472.js]
 # Bug 676989: test hangs consistently on Android
 skip-if = os == "android"