Fix 0012094: ERROR_BUG_READ_ONLY_ACTION_DENIED is not obsoleted

ERROR_BUG_READ_ONLY_ACTION_DENIED is marked as obsolete when it isn't
obsolete at all - it's used in many places throughout the MantisBT
codebase.

On the other hand ERROR_BUG_RESOLVED_ACTION_DENIED isn't used anywhere
within the MantisBT codebase and no language strings exist for this
error code.