add a flag to ec3_image_ioctx_open to always delete an existing image if it already exists

src/image.c

@@ -347,6 +347,12 @@ enum ec3_status ec3_image_ioctx_open(
 	}
 
 	b_path *image_path = b_path_create_from_cstr(path);
+
+	if (mode & EC3_IMAGE_IO_TRUNCATE) {
+		b_path_unlink(image_path);
+		mode &= ~EC3_IMAGE_IO_TRUNCATE;
+	}
+
 	b_file_info image_info;
 	enum b_status status = b_path_stat(image_path, &image_info);
 	enum ec3_status status2 = EC3_ERR_NO_ENTRY;