Minor fix.

Signed-off-by: Cristiano Urban <cristiano.urban@inaf.it>

transfer_service/file_cleaner.py

@@ -74,6 +74,7 @@ class FileCleaner(object):
                 nodeId = row["node_id"]
                 delta = cTime - dTime
                 if delta.days >= self.days and delta.seconds > self.seconds:
+                    if os.path.exists(filePath):
                         os.remove(filePath)
                         self.logger.debug(datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S") + ' ' + filePath)
                     try:
@@ -81,7 +82,7 @@ class FileCleaner(object):
                     except Exception:
                         self.logger.exception(f"FATAL: unable to set the 'phy_deleted_on' flag for VOSpace node having ID = {nodeId}")
                         return
-                    if basePath not in basePaths:
+                    if os.path.exists(basePath) and basePath not in basePaths:
                         basePaths.append(basePath)
             self.logger.info("Removing empty folders (if any)...")
             for basePath in basePaths: