Log Message:
Increase the BUILDLINK_DEPENDS.librsvg2 to 2.6.3nb2.
(I tried using BUILDLINK_RECOMMENDED instead, but it didn't work.)

librsvg2 uses libgsf and libcroco which had changed library SONAMEs
provided.

Problem with old librsvg2 was:
        libgsf-1.so.9 => not found
        libcroco.so.2 => not found