Fix privacy level for test cases

Author: humitos

readthedocs/core/views/__init__.py

@@ -174,8 +174,15 @@ def resolve_404_path(project, version_slug=None, language=None):
         if filename[0] == '/':
             filename = filename[1:]
 
-        version = project.versions.get(slug=version_slug)
-        if version.privacy_level == PRIVATE:
+        version = None
+        if version_slug:
+            version = project.versions.get(slug=version_slug)
+
+        private = any([
+            version and version.privacy_level == PRIVATE,
+            not version and project.privacy_level == PRIVATE,
+        ])
+        if private:
             symlink = PrivateSymlink(project)
         else:
             symlink = PublicSymlink(project)