Fix two edge cases in ResponseCacheStrategy#23129

Closed

mpdude wants to merge 2 commits intosymfony:2.7from

webfactory:fix-handling-noncacheable-embedded-response

Commits on Jun 14, 2017

Fix two edge cases when merging private responses or responses with no caching information
mpdude
committed
Undo negated test (mistakenly added while investigating yet another edge case)
mpdude
committed