Raise exception if rotate pages threshold adjusted without --rotate-pages

Fixes Make usage of --rotate-pages-threshold clearer #1309

src/ocrmypdf/cli.py

@@ -9,6 +9,7 @@ import argparse
 from collections.abc import Callable, Mapping
 from typing import Any, TypeVar
 
+from ocrmypdf._defaults import DEFAULT_ROTATE_PAGES_THRESHOLD
 from ocrmypdf._version import PROGRAM_NAME as _PROGRAM_NAME
 from ocrmypdf._version import __version__ as _VERSION
 
@@ -403,7 +404,7 @@ Online documentation is located at:
     )
     advanced.add_argument(
         '--rotate-pages-threshold',
-        default=14.0,
+        default=DEFAULT_ROTATE_PAGES_THRESHOLD,
         type=numeric(float, 0, 1000),
         metavar='CONFIDENCE',
         help="Only rotate pages when confidence is above this value (arbitrary "