Point nginx dockerfile to official repository provided by NGINX, Inc.

library/nginx

@@ -1,6 +1,6 @@
-# maintainer: InfoSiftr <[email protected]> (@infosiftr)
+# maintainer: NGINX Docker Maintainers <[email protected]> (@nginxinc)
 
-latest: git://github.com/docker-library/nginx@d2c7eee53b81ae70f4eb9e3348575b35df136c95
-1: git://github.com/docker-library/nginx@d2c7eee53b81ae70f4eb9e3348575b35df136c95
-1.7: git://github.com/docker-library/nginx@d2c7eee53b81ae70f4eb9e3348575b35df136c95
-1.7.1: git://github.com/docker-library/nginx@d2c7eee53b81ae70f4eb9e3348575b35df136c95
+latest: git://github.com/nginxinc/docker-nginx@3713a0157083eb4776e71f5a5aef4b2a5bc03ab1
+1: git://github.com/nginxinc/docker-nginx@3713a0157083eb4776e71f5a5aef4b2a5bc03ab1
+1.7: git://github.com/nginxinc/docker-nginx@3713a0157083eb4776e71f5a5aef4b2a5bc03ab1
+1.7.5: git://github.com/nginxinc/docker-nginx@3713a0157083eb4776e71f5a5aef4b2a5bc03ab1