[DomCrawler] Fixed image input case sensitive
Merge branch '2.3' into 2.4

* 2.3:
  fixed CS
  [DomCrawler] Fixed image input case sensitive
Merge branch '2.4'

* 2.4:
  Disable 5.6 until it is stable again.
  Update the fixtures.
  fixed CS
  [HttpKernel] fixed default TTL not applied under certain conditions
  Added test when TTL has expired
  [DomCrawler] Fixed image input case sensitive