Revert "image-source: Set default size of color source to canvas size"

This reverts commit 46c5780a77e761416a990d5680593ff3a47405fb.

This needs to be reverted for now because users who did not set a size
on it (left it at default and just stretched it) will now suddenly have
the source's size change out of nowhere.  There needs to be backward
compatibility implementation for this.

plugins/image-source/color-source.c

@@ -101,12 +101,9 @@ static uint32_t color_source_getheight(void *data)
 
 static void color_source_defaults(obs_data_t *settings)
 {
-	struct obs_video_info ovi;
-	obs_get_video_info(&ovi);
-
 	obs_data_set_default_int(settings, "color", 0xFFFFFFFF);
-	obs_data_set_default_int(settings, "width", ovi.base_width);
-	obs_data_set_default_int(settings, "height", ovi.base_height);
+	obs_data_set_default_int(settings, "width", 400);
+	obs_data_set_default_int(settings, "height", 400);
 }
 
 struct obs_source_info color_source_info = {