Limit openfiles-cur to 1024

[trasz]

Summary

Limit the default soft limit of opened file descriptors to 1024.
A lot of software developed for systems without closefrom(2) loops
trying to close all file descriptors from N to the rlimit, all
58977 of them, one syscall per nonexistent fd.

Note that this does not affect the hard rlimit - the process can still
raise the soft limit using setrlimit(2). They do use it, since they are
usually being developed under distributions which set the limit the
exact same way.

[allanjude]

Reviewed by: allanjude

[swills]

Not a fan of this, personally. This default limit on Linux results in a lot of people hitting the limit, being confused, others documenting how to raise it and the first group searching for how to raise it. Doesn't seem like the best idea to have our users have to do that too. I get the motivation, but would rather have close_range or fdwalk. But again, that's just my personal opinion.

[trasz]

Nah. Lets try https://reviews.freebsd.org/D25177 instead.