Unbound 1.7.3 eats too much memory comparing previous version

[ѽ҉ᶬḳ℠]

> Not sure this is OS issue. This time can't do comparison with other
> servers with different platform.
>
> Just guessing leakage.
>

From what I am observing I would concur. The difference though seems
that this end the amount of cached (~ 110 MB) / rss (~ 2MB) memory
remains stable/stagnant but mem_usage keeps on increasing
steadily/relentlessly to no end, well the end being out of memory and in
order to prevent that had to restart unbound already.

Except for dhcp client / dns resolver / time sync there nothing else
running on the box other than unbound 1.7.3