You are attempting to import a cert with the same issuer/serial as an existing cert, but that is not the same cert.
नोंथाङा मोनसे थाखानाय cert बादि एखे दिहुनग्रा/फारिजों cert खौ लाबोनो नाजागासिनो दं, नाथाय बैयो एखे cert नङा।