Fixed Log repr tests on IronPython.
Fixed Log repr tests on IronPython.

Update issue 1584
Fixed tests on IronPython. There str is unicode and stuff like this doesn't work like on CPython or Jython.

fiuba08/robotframework,fiuba08/robotframework,ldtri0209/robotframework,waldenner/robotframework,ldtri0209/robotframework,fiuba08/robotframework,waldenner/robotframework,waldenner/robotframework,waldenner/robotframework,fiuba08/robotframework,ldtri0209/robotframework,ldtri0209/robotframework,waldenner/robotframework,fiuba08/robotframework,ldtri0209/robotframework