Fixed potential security vulnerabilities

nginx.conf

@@ -1,6 +1,6 @@
 server {
     listen 80;
-    server_name yourdomain.com;
+    server_name talawa-admin.com;
 
     root /usr/share/nginx/html;
     index index.html;
@@ -15,10 +15,17 @@ server {
         add_header Access-Control-Allow-Origin *;
         add_header Access-Control-Allow-Methods "GET, POST, OPTIONS";
         add_header Access-Control-Allow-Headers "Content-Type, Authorization";
+        add_header X-Frame-Options "DENY";
+        add_header X-Content-Type-Options "nosniff";
+        add_header X-XSS-Protection "1; mode=block";
+        add_header Referrer-Policy "strict-origin-when-cross-origin";
         proxy_http_version 1.1;
         proxy_set_header Upgrade $http_upgrade;
         proxy_set_header Connection "upgrade";
         proxy_set_header Host $host;
+        proxy_set_header X-Real-IP $remote_addr;
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+        proxy_set_header X-Forwarded-Proto $scheme;
         proxy_cache_bypass $http_upgrade;
     }