erp5.util: fix a bug preventing the test suite to start with recent slapos

Commit a01da084 failed to fix the
handling of parameters in the dealShebang function and the bug is now
triggered since slapos@f834a06f:

$ PATH=...  SLAPOS_TEST_LOG_DIRECTORY=... SLAPOS_TEST_SHARED_PART_LIST=... /bin/sh '-e
' /srv/slapgrid/slappart0/t/.../i/0/bin/runTestSuite ...
runTestSuite: /bin/sh: 0: Illegal option -
26 jobs for master in 0 seconds
Status Job ID Name Coverage
  External
passed ERP5.CodingStyleTest-Master

02:10:38

failed ERP5.PerformanceTest-Master

00:38:56

failed ERP5.UnitTest-Master

02:53:37

failed SlapOS.Eggs.UnitTest-Master.Python2

00:03:21

failed SlapOS.Eggs.UnitTest-Master.Python3

00:01:23

passed Wendelin.UnitTest-Master

00:46:28

failed SlapOS.Eggs.UnitTest-Master.Python2

00:01:12

failed SlapOS.Eggs.UnitTest-Master.Python2

00:02:11

failed SlapOS.Eggs.UnitTest-Master.Python2

00:04:06

failed SlapOS.Eggs.UnitTest-Master.Python2

00:00:50

failed SlapOS.Eggs.UnitTest-Master.Python2

00:02:40

failed SlapOS.Eggs.UnitTest-Master.Python2

00:01:21

failed SlapOS.Eggs.UnitTest-Master.Python2

00:00:59

failed SlapOS.Eggs.UnitTest-Master.Python2

00:01:57

failed SlapOS.Eggs.UnitTest-Master.Python2

00:01:05

failed SlapOS.Eggs.UnitTest-Master.Python3

00:02:03

failed SlapOS.Eggs.UnitTest-Master.Python3

00:01:01

failed SlapOS.Eggs.UnitTest-Master.Python3

00:00:56

failed SlapOS.Eggs.UnitTest-Master.Python3

00:00:52

failed SlapOS.Eggs.UnitTest-Master.Python3

00:02:04

failed SlapOS.Eggs.UnitTest-Master.Python3

00:00:46

failed SlapOS.Eggs.UnitTest-Master.Python3

00:05:05

failed SlapOS.Eggs.UnitTest-Master.Python3

00:01:10

failed SlapOS.Eggs.UnitTest-Master.Python3

00:00:52

failed SlapOS.Eggs.UnitTest-Master.Python3

00:00:51

failed SlapOS.Eggs.UnitTest-Master.Python3

00:01:13