File ninvaders-obey-cflags.patch of Package ninvaders

diff --git a/Makefile b/Makefile
index d815e2f..c68eeeb 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,5 @@
 CC=gcc
-CFLAGS=-O3 -Wall
+CFLAGS+=-Wall
 LIBS=-lncurses
 
 CFILES=globals.c view.c aliens.c ufo.c player.c nInvaders.c