cpu unpickler added

demo_dpr.py

@@ -63,7 +63,7 @@ class CPU_Unpickler(pickle.Unpickler):
 @st.cache(show_spinner=False, allow_output_mutation=True)
 def load_paragraphs(path):
     with open(path, "rb") as fIn:
-        cache_data = pickle.load(fIn)
+        cache_data = CPU_Unpickler(fIn).load(fIn)
         corpus_sentences = cache_data['contexes']
         corpus_embeddings = cache_data['embeddings']