attempt to reduce amount of fetches: if we did not find a commit in local clone we...

attempt to reduce amount of fetches: if we did not find a commit in local clone we need to check that there are no active fetch operations and if there is some, we need to wait for it to finish and try to find commit again

if we don't do that, then when fetch finishes we'll perform one more fetch even though it is unnecessary because commit is already fetched