Revert "mala zmena"

This reverts commit 90e2a318.

wall.c

@@ -19,7 +19,7 @@ void add_post(wall_t *wall, post_t *post) {
 }
 
 post_t *get_post(wall_t *wall, int number) {
-    if (number > 0 && number < wall->num_posts)
+    if (number > 0 && number <= wall->num_posts)
         return wall->posts[number - 1];
     else
         return NULL;