Does the stipulation in creed that the Caliph must be from the Quraysh contradict the Hadith: "Listen and obey, even if a black slave with a head like a raisin is appointed over you"?

The Hadith stating that the Imams are from Quraysh is authentic and متواتر (mutawatir - transmitted by a large number of narrators), and it is a fundamental principle for the condition that the Imam must be from Quraysh, provided that he is chosen. However, if the Imam attains power through force and conquest, obedience to him becomes obligatory, and it is forbidden to rebel against him, even if he were an Abyssinian slave, as stated in the Hadith.