nginx: 1.7.6 (devel)

Closes #33075.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
Gcc: Upstream Patch

The accepted upstream patch is mildly different to the one we currently
ship for Yosemite, most notably because the upstream patch doesn’t
touch libsanitizer.
gcc: update 4.9.1 bottle.