[ports/graphics/GraphicsMagick] portupgrade fails on 4.11

[GalaxyPC.Net]

utility.c: In function `GmSystemCommand':
utility.c:3885: syntax error before `const'
utility.c:3886: `message_p' undeclared (first use in this function)
utility.c:3886: (Each undeclared identifier is reported only once
utility.c:3886: for each function it appears in.)
*** Error code 1

Stop in /usr/ports/graphics/GraphicsMagick/work/GraphicsMagick-1.1.7/magick.
*** Error code 1

Stop in /usr/ports/graphics/GraphicsMagick/work/GraphicsMagick-1.1.7/magick.
*** Error code 1

Stop in /usr/ports/graphics/GraphicsMagick/work/GraphicsMagick-1.1.7.
*** Error code 1

Stop in /usr/ports/graphics/GraphicsMagick.
** Command failed [exit code 1]: /usr/bin/script -qa 
/tmp/portupgrade.5265.0 env UPGRADE_TOOL=portupgrade 
UPGRADE_PORT=GraphicsMagick-1.1.6_3 UPGRADE_PORT_VER=1.1.6_3 make
** Fix the problem and try again.
** Listing the failed packages (*:skipped / !:failed)
        ! graphics/GraphicsMagick (GraphicsMagick-1.1.6_3)      
(compiler error)