fixed square brackets typo
fixed square brackets typo

from
[tekrar girişlidir][reentrant](http://en.wikipedia.org/wiki/Reentrant_%28subroutine%29),
to
[tekrar girişlidir] [reentrant](http://en.wikipedia.org/wiki/Reentrant_%28subroutine%29),

need space after [tekrar girişlidir] for markdown link.
heroku/12factor,heroku/12factor