io: fix port clash in test.

Both run-set_alloc and run-15-timeout used the same port, so they sometimes
got stuck when running in parallel.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

ccan/io/test/run-set_alloc.c

@@ -65,7 +65,7 @@ static void freefn(void *ptr)
 }
 
 #ifndef PORT
-#define PORT "65015"
+#define PORT "65115"
 #endif
 
 struct data {