PLIST error when gtk3 is compiled without doc

[Mayuresh <mayuresh%acm.org@localhost>]

In a recently updated pkgsrc on NetBSD 10.1 amd64, for x11/gtk3, with the
following option settings

    These options are enabled by default:
            cups doc gtk3-atk-bridge introspection wayland
            x11
    
    These options are currently enabled:
            introspection x11

I required the following change in the PLIST

    -${PLIST.doc}share/icons/hicolor/16x16/apps/gtk3-demo-symbolic.symbolic.png
    +share/icons/hicolor/16x16/apps/gtk3-demo-symbolic.symbolic.png

Besides there is a locale issue that required Makefile change. But I am
discussing that on a separate thread.

-- 
Mayuresh