Win32: correct the linkage
Win32: correct the linkage

For unix systems, pkg-config fills the variable
FOO_LIBRARY_DIRS, when looking for the library FOO
In windows, this variable remains empty:
 pkg-config options like '--libs-only-L'
 does not work (Windows has other prefixes)
 e.g. -L is replaced by /LIBPATH

stack-of-tasks/sot-core,stack-of-tasks/sot-core,stack-of-tasks/sot-core