Just remove harmattan-dev from your source-list. This repo isn't active anymore.
RM696-21-3_PR_006:/etc/apt# ls -al sources.list -rw-r--r-- 1 root root 0 Jan 8 14:15 sources.list RM696-21-3_PR_006:/etc/apt# cd sources.list.d/ RM696-21-3_PR_006:/etc/apt/sources.list.d# grep harmattan-dev sdk.list deb http://harmattan-dev.nokia.com/ harmattan/sdk free non-free