Fix cannot concatenate NoneType

chatbot_constructor.py

@@ -47,7 +47,11 @@ def train(message: str = "", regularization: float = 0.0001, dropout: float = 0.
     vocab_size = len(tokenizer.word_index) + 1
     inp_len = input_len
     if data_hash is None:
-        data_hash = hash_str(data)+"_"+str(regularization)+"_"+str(dropout)+"_"+str(learning_rate)+"_"+str(epochs)+"_"+str(emb_size)+"_"+str(inp_len)+"_"+str(kernels_count)+"_"+str(kernel_size)+"_"+str(left_padding)+"_"+end_activation+".keras"
+        if end_activation is not None:
+            data_hash = hash_str(data)+"_"+str(regularization)+"_"+str(dropout)+"_"+str(learning_rate)+"_"+str(epochs)+"_"+str(emb_size)+"_"+str(inp_len)+"_"+str(kernels_count)+"_"+str(kernel_size)+"_"+str(left_padding)+"_"+end_activation+".keras"
+        else:
+            
+            data_hash = hash_str(data)+"_"+str(regularization)+"_"+str(dropout)+"_"+str(learning_rate)+"_"+str(epochs)+"_"+str(emb_size)+"_"+str(inp_len)+"_"+str(kernels_count)+"_"+str(kernel_size)+"_"+str(left_padding)+".keras"
     elif message == "!getmodelhash":
         return data_hash
     else: