don't overwrite .config if it's a symlink (fixes scripts/env problems)

SVN-Revision: 13005

include/toplevel.mk

@@ -48,7 +48,7 @@ prepare-tmpinfo: FORCE
 	touch $(TOPDIR)/tmp/.build
 
 .config: ./scripts/config/conf prepare-tmpinfo $(if $(CONFIG_HAVE_DOT_CONFIG),,FORCE)
-	@+if [ \! -f .config ] || ! grep CONFIG_HAVE_DOT_CONFIG .config >/dev/null; then \
+	@+if [ \! -e .config ] || ! grep CONFIG_HAVE_DOT_CONFIG .config >/dev/null; then \
 		[ -e $(HOME)/.openwrt/defconfig ] && cp $(HOME)/.openwrt/defconfig .config; \
 		$(_SINGLE)$(NO_TRACE_MAKE) menuconfig $(PREP_MK); \
 	fi