Added handling for OSError caused by trying to load a GNU readline shared library in

Python environments like PyPy which have a pure Python implementation of readline.

Author: kmvanbrunt

cmd2/rl_utils.py

@@ -129,10 +129,10 @@ def pyreadline_remove_history_item(pos: int) -> None:
             import ctypes
 
             readline_lib = ctypes.CDLL(readline.__file__)
-        except AttributeError:  # pragma: no cover
+        except (AttributeError, OSError):  # pragma: no cover
             _rl_warn_reason = (
                 "this application is running in a non-standard Python environment in\n"
-                "which readline is not loaded dynamically from a shared library file."
+                "which GNU readline is not loaded dynamically from a shared library file."
             )
         else:
             rl_type = RlType.GNU