error: You have not concluded your merge (MERGE_HEAD exists). hint: Please, commit your changes before merging. fatal: Exiting because of unfinished merge.
Undo the merge and pull again.
To undo a merge:
git merge --abort [Since git version 1.7.4]
git reset --merge [prior git versions]
Resolve the conflict.
Don't forget to add and commit the merge.
git pull now should work fine.