add missing function clause repair_keys_range in convert_fold

[hmmr]

This is to unbreak aae_fold for repair_keys_range.

In collaboration with @pjaclark.

[martinsumner]

As I understand it convert_fold is only used normally via riak_client:aae_fold/1. However this is broken too:

riak_kv/src/riak_client.erl

Lines 905 to 911 in 9ca7184

	Q0 = riak_kv_clusteraae_fsm:convert_fold(Query),
	case riak_kv_clusteraae_fsm:is_valid_fold(Q0) of
	true ->
	riak_kv_clusteraae_fsm_sup:start_clusteraae_fsm(Node,
	[{raw, ReqId, Me},
	[Query, TimeOut]]),
	wait_for_fold_results(ReqId, TimeOut);

The Q0 is used in the validity check, but not in the actual query (where Query is used).

Do you want to make this quick fix as part of this PR, and pass Q0 through to the query?

I have a riak_test ready. This test extends verify_aaefold_rangerepair so that it works via riak_client when depending on the date conversion: https://github.com/basho/riak_test/blob/mas-1839-convertfold/tests/verify_aaefold_rangerepair.erl.

If you update the PR with the second fix, the test should pass