Update tranlation text domain

sunrise.php

@@ -66,6 +66,8 @@ foreach ([$wu_sunrise, $wu_mu_sunrise] as $wu_sunrise_file) {
 	}
 }
 unset($wu_sunrise_file);
+unset($wu_mu_sunrise);
+unset($wu_sunrise);
 /**
  * Include Mercator.
  *
@@ -81,6 +83,7 @@ $wu_mercator = defined('WP_PLUGIN_DIR')
 if (file_exists($wu_mercator)) {
 	require $wu_mercator;
 }
+unset($wu_mercator)
 
 /**
  * Adds a warning when WP Multisite WaaS is not present but the sunrise file is.