Fix Activesync.

Address the issue after shore.co.il was moved to ns4.

snippets/z-push.conf → snippets/activesync.conf

 location /AutoDiscover/ {
-    proxy_pass          https://$z_push$request_uri;
+    proxy_pass          https://zpush.shore.co.il$request_uri;
     include             snippets/proxy-headers.conf;
 }
 
 location /Autodiscover/ {
-    proxy_pass          https://$z_push$request_uri;
+    proxy_pass          https://zpush.shore.co.il$request_uri;
     include             snippets/proxy-headers.conf;
 }
 
 location /autodiscover/ {
-    proxy_pass          https://$z_push$request_uri;
+    proxy_pass          https://zpush.shore.co.il$request_uri;
     include             snippets/proxy-headers.conf;
 }
 
 location /Microsoft-Server-ActiveSync {
-    proxy_pass          https://$z_push$request_uri;
+    proxy_pass          https://zpush.shore.co.il$request_uri;
     include             snippets/proxy-headers.conf;
 }