use gb_LINKEROPTFLAGS if no explicit LDFLAGS is given
use gb_LINKEROPTFLAGS if no explicit LDFLAGS is given

I have no idea why gb_LINKEROPTFLAGS stopped working, it used to be used
and I can't find the commit that removed it.

Change-Id: I537e4e7b686ecc34022f2097fa3e666295294e04

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core