Remove initial pledge(2) that doesn't give us much protection since it's so

Remove initial pledge(2) that doesn't give us much protection since it's so
short lived, we either go directly exiting the program or just a few lines
below we call pledge(2) again, where it actually should be, and with really
reduced promises. Next commit will restrict further access to the filesystem
through unveil(2).

OK deraadt@ kn@