Attempt to fix travis build

src/sdl/rect.cpp

@@ -22,7 +22,17 @@ bool point_in_rect(int x, int y, const SDL_Rect& rect)
 {
 	SDL_Point p {x, y};
 
+	/* This check is here because Travis CI builds with SDL 2.0.2.
+	 * The code isn't intended to be skipped: end users, distribution packagers etc.
+	 * should build the game with SDL 2.0.4 or above.
+	 *
+	 * - vultraz, 2017-06-18
+	 */
+#if SDL_VERSION_ATLEAST(2, 0, 4)
 	return SDL_PointInRect(&p, &rect);
+#else
+	return false;
+#endif
 }
 
 bool point_in_rect(const gui2::point& point, const SDL_Rect& rect)