nginx: content injection should be supported on nginx

[zimmerle]

Following test cases are failing:

from: regression/action/10-append-prepend.t
response content failed to match: (?^:APPEND: test$)
1) action - append content: failed
response content failed to match: (?^:^PREPEND: test)
2) action - prepend content: failed
Passed: 0; Failed: 2

[zimmerle]

By having SecResponseBodyAccess set to On, it is possible to inject content on nginx. Getting it closer to Apache.

[zimmerle]

Fixed by: 2a43589