WARNing when someone has over 50 non-terminal allocs was just too
confusing.
Tested manually with `gc_max_allocs = 10` and bumping a job from `count
= 19` to `count = 21`:
```
2017/11/02 17:54:21.076132 [INFO] client.gc: garbage collection due to number of allocations (19) is over the limit (10) skipped because no terminal allocations
...
2017/11/02 17:54:48.634529 [WARN] client.gc: garbage collection due to number of allocations (21) is over the limit (10) skipped because no terminal allocations
```