Revert "[gobject] Change gobject import to fix tests generation."

This reverts commit cd7224dfdda3c532028bbef37fd6813af7b9a4a0.

rpm builds fails:
Traceback (most recent call last):
  File "generate-tests-xml.py", line 78, in <module>
    content += getTestCases(mod, testScript)
  File "generate-tests-xml.py", line 48, in getTestCases
    loc = __import__(module, globals(), locals(), [])
  File "/home/x/rpmbuild/BUILD/tumbler/tests/tumblerImageFormatsUnitTests.py", line 8, in <module>
    from TumblerService.Tumbler import Tumbler
  File "/home/x/rpmbuild/BUILD/tumbler/tests/TumblerService/Tumbler.py", line 6, in <module>
    import gobject
ImportError: No module named gobject