put config.h dependency into the Makefile

Makefile

@@ -2,5 +2,5 @@ TARGET=fiboBG
 SRC=main.c
 # DEBUG=-g
 DEBUG=
-$(TARGET): main.c
+$(TARGET): main.c config.h
 	gcc -Wall -Wextra $(DEBUG) $(SRC) `pkg-config --cflags --libs cairo x11` -o $(TARGET) -lm

config.h

@@ -1,4 +1,3 @@
-
 typedef struct _color {
     float red;
     float green;