repoview: stop recomputing cached key in all case As explained in the comment, we were computing the key of the cache value every time because of some obscure MQ test failure. I've dropped that code and ran the test again that failure is gone. I assume some transaction cleanup got rid of it. So we are dropping that code. This provide a significant speedup. Testing `hg log` on Mozilla-central this reduce the time spent on changelog cache validation by a third: before: 19.5s of 80s after: 12.2s of 69s (With stupid python profiler overhead)