[1.7.x] Fixed copy/paste typos in StreamingHttpResponse doc.
[1.7.x] Fixed copy/paste typos in StreamingHttpResponse doc.

Backport of e9c730f6be from master

oscaro/django,oscaro/django,jyotsna1820/django,oscaro/django,jyotsna1820/django,oscaro/django,jyotsna1820/django,jyotsna1820/django