Default path includes the string %%LOCALBASE%%. This was intended to be replaced
with the real value of LOCALBASE by the port Makefile at some point, but it
isn't at the moment.

Set this value in the Makefile by defining CPPFLAGS accordingly.

PR: 217451
Submitted by: Dan McGregor <dan.mcgregor@usask.ca>
MFH: 2017Q1 (blanket)