tell make to pass along information for paralell build to build.sh

since we make the ExternalLibrary using a script build.sh, make does not
recognize it as a sub-make and does not pass along the required env variables
unless we prefix by "+"


git-svn-id: http://svn.cactuscode.org/projects/ExternalLibraries/LORENE/trunk@66 5c1b1641-b641-47ec-b3d9-0f93d4c445ee

src/make.code.deps

@@ -9,4 +9,4 @@ export LORENE_INSTALL_DIR
 
 $(CCTK_TARGET) $(OBJS) $(SRCS:%=%.d): $(SCRATCH_BUILD)/done/$(THORN)
 $(SCRATCH_BUILD)/done/$(THORN): $(SRCDIR)/build.sh
-	$(SRCDIR)/build.sh
+	+$(SRCDIR)/build.sh