Fix import and return integer file size

Script/utils.py

@@ -2,6 +2,7 @@
 __version__='$Revision$'
 
 import logging
+from subprocess import *
 
 #### Set Log severity level #####
 def set_log_level(level, logger):
@@ -68,7 +69,7 @@ def castorinfo(castorfile, castorenv, logger):
         try:
             splitted = nslsOut.split()
 
-            size = splitted[4]
+            size = int(splitted[4])
 
             id = splitted.index('AD')
             checksum = nslsOut.split()[id+1]