fix abcapi host in sslproxy

dockerfiles/services/sslproxy/hosts/abcapi.xai-corp.net.conf

@@ -21,12 +21,12 @@ server {
     add_header Strict-Transport-Security "max-age=15768000; includeSubDomains" always;
 
     location / {
-        proxy_pass $upstream_addr;
+        proxy_pass $backend;
         proxy_set_header Host              $host;   # required for docker client's sake
         proxy_set_header X-Real-IP         $remote_addr; # pass on real client's IP
         proxy_set_header X-Forwarded-For   $proxy_add_x_forwarded_for;
         proxy_set_header X-Forwarded-Proto $scheme;
         proxy_set_header Connection $http_connection;
-    }
+       }
 
 }