Update overview.rst with typos in nginx conf.

Minor correction in the production nginx server conf with proxy_redirect as off; previously it was false.
Merge pull request #1037 from toanant/patch-1

Update overview.rst with typos in nginx conf.
Add SystemError to errors from compilation

OSX generates a SystemError from a missing compiler; trap with other
compilation errors.
Merge branch 'stable' into branch3.2