There is no contradiction between the two verses. There is no abrogation by one verse of the other. The justice that is mentioned in the first verse is the justice within ones ability, which is related to being fair in division of time and maintenance.
As for being just with respect to love and sexual relations, this is not within ones ability. This is what is being referred to in this verse;
''You will never be able to do perfect justice between your wives even if it is your ardent desire .” an-Nisa : 129
In a hadeeth about the Prophet (sallallaahu ‘alaihi-wasallam), Aisha [ may Allah be Pleased with her] stated,
''The Messenger of Allah (sallallaahu ‘alaihi-wasallam) used to divide his time between his wives and he was fair. He used to say. ‘ O Allah, that is my division with respect to what I have control over. Do not blame me for what You control and over which I have no control.’ ‘’
This was recorded by Abu Dawud, al- Tirmidhi, al- Nasai, Ibn Majah. It is graded Sahih by ibn Hibban and al- Haakim.