fix: set default vllm backend for gguf

src/pages/llmodels/forms/index.tsx

@@ -241,14 +241,6 @@ const DataForm: React.FC<DataFormProps> = forwardRef((props, ref) => {
       ...updateGPUSelector(val)
     });
 
-    const imageName = form.getFieldValue('image_name');
-    const runCommand = form.getFieldValue('run_command');
-
-    // if the image_name or run_command is empty, set them to default value of the backend
-
-    if (val === backendOptionsMap.custom && !imageName && !runCommand) {
-      return;
-    }
     onBackendChange?.(val);
   };