ticket 50510 - etime can contain invalid nanosecond value
    
    Bug Description:
    	When running the test on upstream backported version, the skipif line has to be manually commented
    
    Fix description :
    	changed skifif to xfail, the test being written so that it is able to manage the failures.
    	This is a temporary fix, as the test will have to be modified when bug 1749236 related to this feature will be fixed.