Fix: Improve handling of unknown scan ids

Don't print a traceback if a scan_id is not available. Instead safely
handle this case and log a warning.

(cherry picked from commit 51d84e0)

Author: bjoernricks

ospd_openvas/daemon.py

@@ -850,7 +850,12 @@ def report_results(self, results: list, scan_id: str) -> bool:
             with following fields: result_type, host_ip, host_name, port, oid,
             value, uri (optional)
 
+        Returns:
+            True if the results have been reported
         """
+        if not self.scan_collection.id_exists(scan_id):
+            logger.warning("Unknown scan_id %s", scan_id)
+            return False
 
         vthelper = VtHelper(self.nvti)