[MacPorts] #28385: libpng: update to 1.5.x

[MacPorts]

#28385: libpng: update to 1.5.x
----------------------------------------+-----------------------------------
 Reporter:  rmstonecipher@…             |       Owner:  rmstonecipher@…           
     Type:  update                      |      Status:  new                       
 Priority:  Normal                      |   Milestone:                            
Component:  ports                       |     Version:                            
 Keywords:  haspatch                    |        Port:  libpng                    
----------------------------------------+-----------------------------------

Comment(by cal@…):

 Yes, it is. MPAB (and thus the buildbots) have no implementation of rev-
 upgrade, so the revbump is still needed to get the buildbots to rebuild
 the broken packages.

-- 
Ticket URL: <https://trac.macports.org/ticket/28385#comment:15>
MacPorts <http://www.macports.org/>
Ports system for Mac OS