Update INSTALL_DEV_Ubuntu_16.04.md upgrade Datasources section

Documentation/For_ops/INSTALL/INSTALL_DEV_Ubuntu_16.04.md

@@ -274,13 +274,27 @@ Replace `my-password` with suitable value.
 Adjust Postgres credentials in `config/app.php`, search for 'Datasources'
 and 'default'. Now adjust:
 
-* host
-* port
-* username
-* password
-* database
-
-* Datasource for debug-kit
+```php
+'default' => [
+            'className' => 'Cake\Database\Connection',
+            'driver' => 'Cake\Database\Driver\Postgres',
+            'persistent' => false,
+            'host' => 'localhost',
+            //'port' => 'non_standard_port_number',
+            'username' => 'comptoir',
+            'password' => 'comptoir',
+            'database' => 'comptoir',
+            'encoding' => 'utf8',
+            'timezone' => 'Europe/Paris',
+            'cacheMetadata' => true,
+            'log' => false,
+```
+You should comment the 'test' section of Datasources.
+
+
+## APP.PHP Configure debug-kit database credentials
+
+* Add datasource for debug-kit
 
 ```php
     'debug_kit' => [