MFH: r541873 r543274

Re-enable the pnmquant test, which was fixed in 10.89.

Approved by: tobik

graphics/netpbm: Update to 10.91.01

Changes: https://github.com/t6/netpbm/blob/v10.91.01/doc/HISTORY

Approved by: ports-secteam bug fix blanket