[MacPorts] #45966: gtk3 @3.14.5 +quartz : cherry pick a recent commit to fix a missing GTK_IS_PLUG?

[MacPorts]

#45966: gtk3 @3.14.5 +quartz : cherry pick a recent commit to fix a missing
GTK_IS_PLUG?
---------------------------+--------------------
  Reporter:  gellule.xg@…  |      Owner:  cal@…
      Type:  defect        |     Status:  closed
  Priority:  Normal        |  Milestone:
 Component:  ports         |    Version:  2.3.3
Resolution:  fixed         |   Keywords:
      Port:  gtk3          |
---------------------------+--------------------

Comment (by cal@…):

 OK, in this case r128500.

-- 
Ticket URL: <https://trac.macports.org/ticket/45966#comment:5>
MacPorts <https://www.macports.org/>
Ports system for OS X