FIX: substitutions THIRDPARTY_XXX are not available for actioncomm reminders (#31385)

Author: thomas-Ngr

htdocs/comm/action/class/actioncomm.class.php

@@ -2341,6 +2341,7 @@ public function sendEmailsReminder()
 
 					// Load event
 					$res = $this->fetch($actionCommReminder->fk_actioncomm);
+					if ($res > 0) $res = $this->fetch_thirdparty();
 					if ($res > 0) {
 						// PREPARE EMAIL
 						$errormesg = '';