pf: Increate default state table size

The typical system now has a lot more memory than when pf was new, and is also
expected to handle more connections. Increase the default size of the state
table.
Note that users can overrule this using 'set limit states' in pf.conf.

From OpenBSD:

The year is 2018.
Mercury, Bowie, Cash, Motorola and DEC all left us.
Just pf still has a default state table limit of 10000.
Had! Now it's a tiny little bit more, 100k.
lead guitar: me
ok chorus: phessler theo claudio benno
background school girl laughing: bob

Obtained from: OpenBSD