FIX: TransferAgent TypeError

To prevent ```TypeError``` when executing failover registration: 
```
2013-02-01 17:04:05 UTC DataManagement/TransferAgent EXCEPT: == EXCEPTION ==
2013-02-01 17:04:05 UTC DataManagement/TransferAgent EXCEPT: <type 'exceptions.TypeError'>:'long' object is not iterable
2013-02-01 17:04:05 UTC DataManagement/TransferAgent EXCEPT:   File "/opt/dirac/pro/DIRAC/Core/Base/AgentModule.py", line 314, in am_secureCall
2013-02-01 17:04:05 UTC DataManagement/TransferAgent EXCEPT:     result = functor( *args )
2013-02-01 17:04:05 UTC DataManagement/TransferAgent EXCEPT: 
2013-02-01 17:04:05 UTC DataManagement/TransferAgent EXCEPT:   File "/opt/dirac/pro/DIRAC/DataManagementSystem/Agent/TransferAgent.py", line 516, in execute
2013-02-01 17:04:05 UTC DataManagement/TransferAgent EXCEPT:     executeFTS = self.executeFTS( requestDict )
2013-02-01 17:04:05 UTC DataManagement/TransferAgent EXCEPT: 
2013-02-01 17:04:05 UTC DataManagement/TransferAgent EXCEPT:   File "/opt/dirac/pro/DIRAC/DataManagementSystem/Agent/TransferAgent.py", line 588, in executeFTS
2013-02-01 17:04:05 UTC DataManagement/TransferAgent EXCEPT:     schedule = self.schedule( requestDict )
2013-02-01 17:04:05 UTC DataManagement/TransferAgent EXCEPT: 
2013-02-01 17:04:05 UTC DataManagement/TransferAgent EXCEPT:   File "/opt/dirac/pro/DIRAC/DataManagementSystem/Agent/TransferAgent.py", line 688, in schedule
2013-02-01 17:04:05 UTC DataManagement/TransferAgent EXCEPT:     registerFiles = self.registerFiles( requestObj, iSubRequest )
2013-02-01 17:04:05 UTC DataManagement/TransferAgent EXCEPT: 
2013-02-01 17:04:05 UTC DataManagement/TransferAgent EXCEPT:   File "/opt/dirac/pro/DIRAC/DataManagementSystem/Agent/TransferAgent.py", line 1015, in registerFiles
2013-02-01 17:04:05 UTC DataManagement/TransferAgent EXCEPT:     register = self.transferDB().setRegistrationDone( channelID, fileID )
2013-02-01 17:04:05 UTC DataManagement/TransferAgent EXCEPT: 
2013-02-01 17:04:05 UTC DataManagement/TransferAgent EXCEPT:   File "/opt/dirac/pro/DIRAC/DataManagementSystem/DB/TransferDB.py", line 1222, in setRegistrationDone
2013-02-01 17:04:05 UTC DataManagement/TransferAgent EXCEPT:     "WHERE FileID IN (%s) AND ChannelID=%s AND Status='Waiting';" % ( intListToString( fileID ), channelID )
2013-02-01 17:04:05 UTC DataManagement/TransferAgent EXCEPT: 
2013-02-01 17:04:05 UTC DataManagement/TransferAgent EXCEPT:   File "/opt/dirac/pro/DIRAC/Core/Utilities/List.py", line 90, in intListToString
2013-02-01 17:04:05 UTC DataManagement/TransferAgent EXCEPT:     return ",".join( [str( x ) for x in aList ] )
2013-02-01 17:04:05 UTC DataManagement/TransferAgent EXCEPT: ===============
```