[MacPorts] #69924: opencv3: update to 3.4.20

[MacPorts]

#69924: opencv3: update to 3.4.20
-------------------------------------+----------------------
  Reporter:  mohd-akram              |      Owner:  mascguy
      Type:  update                  |     Status:  assigned
  Priority:  Normal                  |  Milestone:
 Component:  ports                   |    Version:
Resolution:                          |   Keywords:
      Port:  opencv3, opencv3-devel  |
-------------------------------------+----------------------
Changes (by mohd-akram):

 * owner:  (none) => mascguy
 * status:  new => assigned
 * cc: mascguy (removed)


-- 
Ticket URL: <https://trac.macports.org/ticket/69924#comment:1>
MacPorts <https://www.macports.org/>
Ports system for macOS