Ensuring that drush policy applies only to AC. (#693)

Author: grasmash

template/drush/policy.drush.inc

@@ -6,7 +6,10 @@
  * Alter alias record data in code.
  */
 function policy_drush_sitealias_alter(&$alias_record) {
-  if ($alias_record['path-aliases']['%drush-script'] == 'drush9') {
+  if (!empty($alias_record['uri'])
+    && strstr($alias_record['uri'], 'acquia') !== FALSE
+    && !empty($alias_record['path-aliases']['%drush-script'])
+    && $alias_record['path-aliases']['%drush-script'] == 'drush9') {
     // Acquia Cloud does not currently support drush9.
     $alias_record['path-aliases']['%drush-script'] = 'drush8';
   }