Replace _forward_modules() with explicit named_modules() call (CI fix)

eli5/pytorch/explain_prediction.py

@@ -199,7 +199,7 @@ def _maybe_image_module(module):
     """Check if module has "image-like" layers"""
     # check that we have some layer that has '2d' in its name
     l = _search_layer(module,
-                      _forward_modules,
+                      module.named_modules(),
                       lambda module, name, layer:
                       '2d' in _get_module_name(layer).casefold()
                       )