Fix referenced before assignment error

app.py

@@ -50,6 +50,7 @@ def train(data: str, message: str):
         dense4_layer = Dense(100, activation="tanh")(dense3_layer)
         concat2_layer = Concatenate()([dense4_layer, prelu1_layer, attn_flatten_layer, conv1_flatten_layer])
         dense4_layer = Dense(resps_len, activation="softmax")(concat2_layer)
+        model = Model(inputs=input_layer, outputs=dense4_layer)
         
         X = []
         y = []