trying to set nginx wp-multisite keep getting 500 Internal Server Error

I am following https://rtcamp.com/wordpress-nginx/tutorials/multisite/subdomains/minimal/ to try and set up nginx - wp-multi site.

I keep getting 500 internal server error

Dont know why.

The following is my config files:

nginx.conf file:
----------------------------------------------------------
user www-data;
worker_processes 2;
pid /run/nginx.pid;

events {
worker_connections 1024;
# multi_accept on;
}

http {
sendfile on;
tcp_nopush on;
tcp_nodelay on;
keepalive_timeout 65;
types_hash_max_size 2048;
include /etc/nginx/mime.types;
default_type application/octet-stream;
access_log /var/log/nginx/access.log;
error_log /var/log/nginx/error.log;
gzip on;
gzip_disable "msie6";
# gzip_vary on;
# gzip_proxied any;
# gzip_comp_level 6;
# gzip_buffers 16 8k;
# gzip_http_version 1.1;
# gzip_types text/plain text/css application/json application/x-javascript text/xml application/xml applicatio$
include /etc/nginx/sites-enabled/*;
}
----------------------------------------------------------

This is my server specific file inside site-enabled:
----------------------------------------------------------
server {
server_name mygametests.info *.mygametests.info ;
access_log /var/log/nginx/mygametests.info.access.log;
error_log /var/log/nginx/mygametests.info.error.log;

root /usr/share/nginx/html/mygametests/htdocs;
index index.php;

location / {
try_files $uri $uri/ /index.php?$args ;
}

location ~ \.php$ {
try_files $uri /index.php;
include fastcgi_params;
fastcgi_pass unix:/var/run/php5-fpm.sock;
}

location ~* ^.+\.(ogg|ogv|svg|svgz|eot|otf|woff|mp4|ttf|rss|atom|jpg|jpeg|gif|png|ico|zip|tgz|gz|rar|bz2|doc|xls|exe|ppt|tar|mid|midi|wav|bmp|rtf)$ {
access_log off; log_not_found off; expires max;
}

location = /robots.txt { access_log off; log_not_found off; }
location ~ /\. { deny all; access_log off; log_not_found off; }
}

----------------------------------------------------------
My errors log files:

file: mygametests.info.error.log

`2014/02/21 03:10:54 [error] 3191#0: *1 rewrite or internal redirection cycle while internally redirecting to "/index.php", client: xxx.xxx.xxx.xxx, server: mygametests.info, request: "GET /wp-admin$`

file: mygametests.info.access.log

`xxx.xxx.xxx.xxx - - [21/Feb/2014:03:10:54 +0000] "GET /wp-admin HTTP/1.1" 500 201 "-" "Mozilla/5.0 (Windows NT 6.3; WOW64; rv:27.0) Gecko/20100101 Firefox/27.0"`

I know this is a long question have been at this for long time now any help would be highly appreciated