sysutils/py-salt-2019: Fix build (extract) with static bsdtar(1)

> Extracting for py37-salt-2019-2019.2.8

> SHA256 Checksum OK for salt-2019.2.8.tar.gz.

tar: Pathname can't be converted from UTF-8 to current locale.
tar: Pathname can't be converted from UTF-8 to current locale.
tar: Pathname can't be converted from UTF-8 to current locale.
tar: Pathname can't be converted from UTF-8 to current locale.
tar: Pathname can't be converted from UTF-8 to current locale.
tar: Error exit delayed from previous errors.

> Failed to extract "/portdistfiles//salt-2019.2.8.tar.gz".

• Error code 1

See more details for the same issue in bug 246618.

Reported by: pkg-fallout
Approved by: portmgr blanket