Added 'close()' instruction.

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

transfer_service/tape_client.py

@@ -155,6 +155,7 @@ class TapeClient(object):
         else:
             for f in fileList:
                 fp.write(f"{f}\n")
+            fp.close()
             self.copy(f"./{tmp}", f"/tmp/{tmp}")
             os.remove(f"./{tmp}")
             cmd = f"{self.EEADM} migrate /tmp/{tmp} -p {tapePool}"
@@ -188,6 +189,7 @@ class TapeClient(object):
         else:
             for f in fileList:
                 fp.write(f"{f}\n")
+            fp.close()
             self.copy(f"./{tmp}", f"/tmp/{tmp}")
             os.remove(f"./{tmp}")
             cmd = f"{self.EEADM} recall /tmp/{tmp}"