adding service detection to pg templates

javascript/enumeration/pgsql/pgsql-version-detect.yaml

@@ -14,7 +14,11 @@ info:
     shodan-query: "product:\"PostgreSQL\""
   tags: js,network,postgresql,enum,authenticated
 javascript:
-  - code: |
+  - pre-condition: |
+      var m = require("nuclei/postgres");
+      var c = m.PGClient();
+      c.IsPostgres(Host, Port);
+    code: |
       const postgres = require('nuclei/postgres');
       const client = new postgres.PGClient;
       connected =  client.ExecuteQuery(Host, Port, User, Pass, Db, "select version();");