Makefile: test-parse-options depends on parse-options.h

Signed-off-by: Junio C Hamano <gitster@pobox.com>

Makefile

@@ -1524,6 +1524,8 @@ test-delta$X: diff-delta.o patch-delta.o
 
 test-parse-options$X: parse-options.o
 
+test-parse-options.o: parse-options.h
+
 .PRECIOUS: $(patsubst test-%$X,test-%.o,$(TEST_PROGRAMS))
 
 test-%$X: test-%.o $(GITLIBS)