Fix camera index for UVC cameras

src/parse.c

@@ -558,9 +558,8 @@ libmegapixels_load_uvc(libmegapixels_devconfig *config)
 			if (config->cameras == NULL) {
 				return -1;
 			}
-			config->cameras[config->count++] = camera;
 			camera->index = config->count;
-
+			config->cameras[config->count++] = camera;
 		}
 	}