[MacPorts] #53022: opencv @3.1.0_6+python34: Portfile broken for variant +python34

[MacPorts]

#53022: opencv @3.1.0_6+python34: Portfile broken for variant +python34
----------------------+----------------------
  Reporter:  detlevd  |      Owner:  stromnov
      Type:  defect   |     Status:  assigned
  Priority:  Normal   |  Milestone:
 Component:  ports    |    Version:  2.3.4
Resolution:           |   Keywords:
      Port:  opencv   |
----------------------+----------------------
Changes (by RJVB):

 * Attachment "opencv-python-fix.diff" added.

 fix the +python34 build issue (and removes an inexistant CMake option). A
 revbump is not required.

--
Ticket URL: <https://trac.macports.org/ticket/53022>
MacPorts <https://www.macports.org/>
Ports system for macOS