libobs: Remove obs_get_default_rect_effect()

Originally removed in 0.12.1 but "temporarily" brought
back, then never removed.

libobs/obs.c

@@ -2143,12 +2143,6 @@ gs_effect_t *obs_get_base_effect(enum obs_base_effect effect)
 	return NULL;
 }
 
-/* OBS_DEPRECATED */
-gs_effect_t *obs_get_default_rect_effect(void)
-{
-	return obs->video.default_rect_effect;
-}
-
 signal_handler_t *obs_get_signal_handler(void)
 {
 	return obs->signals;

libobs/obs.h

@@ -746,12 +746,6 @@ enum obs_base_effect {
 /** Returns a commonly used base effect */
 EXPORT gs_effect_t *obs_get_base_effect(enum obs_base_effect effect);
 
-#ifndef SWIG
-/* DEPRECATED: gets texture_rect default effect */
-OBS_DEPRECATED
-EXPORT gs_effect_t *obs_get_default_rect_effect(void);
-#endif
-
 /** Returns the primary obs signal handler */
 EXPORT signal_handler_t *obs_get_signal_handler(void);