apng2gif, fix libpng16 reference (#3771)
apng2gif, fix libpng16 reference (#3771)


haikuports/haikuports,haikuports/haikuports,Begasus/haikuports,haikuports/haikuports,moochris/haikuports,Begasus/haikuports,haikuports/haikuports,Begasus/haikuports,Begasus/haikuports,nielx/haikuports,nielx/haikuports,moochris/haikuports,Begasus/haikuports,nielx/haikuports,moochris/haikuports,haikuports/haikuports