Crash when executable is missing in configuration file

[lxavier]

We get :

Traceback (most recent call last):
File "./src/testsuite.py", line 331, in
main()
File "./src/testsuite.py", line 263, in main
mytest = Test(child, options, conf, logger)
File "./src/./tools/ts_test.py", line 91, in init
raise SkipError('An executable must be defined in the command line or in testlist.xml')
ts_error.SkipError: An executable must be defined in the command line or in testlist.xml

instead of a proper error msg