libobs: Fix ABI break

OBS_EFFECT_AREA from 7d811499e was inserted in the middle of the enum,
which breaks ABI for any binaries that use
OBS_EFFECT_PREMULTIPLIED_ALPHA or OBS_EFFECT_BILINEAR_LOWRES.

libobs/obs.h

@@ -600,10 +600,10 @@ enum obs_base_effect {
 	OBS_EFFECT_SOLID,              /**< RGB/YUV (solid color only) */
 	OBS_EFFECT_BICUBIC,            /**< Bicubic downscale */
 	OBS_EFFECT_LANCZOS,            /**< Lanczos downscale */
-	OBS_EFFECT_AREA,               /**< Area rescale */
 	OBS_EFFECT_BILINEAR_LOWRES,    /**< Bilinear low resolution downscale */
 	OBS_EFFECT_PREMULTIPLIED_ALPHA,/**< Premultiplied alpha */
 	OBS_EFFECT_REPEAT,             /**< RGB/YUV (repeating) */
+	OBS_EFFECT_AREA,               /**< Area rescale */
 };
 
 /** Returns a commonly used base effect */