Handle no indicators provided in `sms_attachments.py`

mvt/ios/modules/mixed/sms_attachments.py

@@ -54,6 +54,9 @@ class SMSAttachments(IOSExtraction):
         }
 
     def check_indicators(self) -> None:
+        if not self.indicators:
+            return
+
         for attachment in self.results:
             # Check for known malicious filenames.
             if self.indicators.check_file_path(attachment["filename"]):