add "dim_model_base" to config.json to fix llama.cpp support

config.json

@@ -15,6 +15,7 @@
   "pad_token_id": 2,
   "hidden_act": "silu",
   "hidden_size": 4096,
+  "dim_model_base": 256,
   "initializer_range": 0.1,
   "intermediate_size": 16384,
   "max_position_embeddings": 32768,