sysutils/py-salt: fix commands like "service salt_minion status"

When py-processtitle is installed, the master and minion daemons will
change their process titles in a way that breaks commands like "service
salt_minion status". status, stop, restart, etc are all broken. Fix
this bug by:

• Always installing py-processtitle unconditionally,
• Fixing utils/process.py to not insert an extra space in the title
• Adjusting the RC scripts accordingly

A downside is that many service subcommands will now print this harmless
warning message:

/usr/local/etc/rc.d/salt_minion: WARNING: cannot read shebang line from
MultiMinionProcessManager

Approved by: krion (maintainer)
Sponsored by: ConnectWise
PR: 285053