Update Nginx to 1.26.2 (GH-28)

That is the latest stable version, and certainly progress over Nginx
1.17.6 which has been released almost five years ago.

Author: cmb69

pgo/tpl/nginx/phpsdk_pgo.json

@@ -1,5 +1,5 @@
 {
-	"pkg_url": "https://nginx.org/download/nginx-1.17.6.zip",
+	"pkg_url": "https://nginx.org/download/nginx-1.26.2.zip",
 	"host": "127.0.0.1",
 	"port": 8081
 }