Make python bindings build when using a separate build directory.

Don't symlink a (possibly non-existant) file from the source
tree on top of gnucash_core_c.py which was just generated by
swig in the build tree.

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@22237 57a11ea4-9604-0410-9ed3-97b8803252fd

src/optional/python-bindings/Makefile.am

@@ -109,7 +109,7 @@ PYTHON_LINK_FILES = \
 	$(RM) -rf gnucash
 	mkdir -p gnucash
 if GNUCASH_SEPARATE_BUILDDIR
-	for X in ${PYTHON_LINK_FILES} ; do \
+	for X in $(filter-out gnucash_core_c.py,${PYTHON_LINK_FILES}) ; do \
 	  $(LN_S) -f ${srcdir}/$$X . ; \
 	done
 endif