[Bug] 配置ollama 之后，使用报错

### 📦 Deployment Method

Official installation package

### 📌 Version

v2.15.1

### 💻 Operating System

Windows

### 📌 System Version

WIN11 专业版 23H2

### 🌐 Browser

Firefox

### 📌 Browser Version

130.0 64位

### 🐛 Bug Description

https://docs.nextchat.dev/models/ollama 根据这个配置ollama 之后，使用报错：
{
"error": true,
"message": "Failed to fetch"
}
{
"error": true,
"message": "empty response from server"
}

### 📷 Recurrence Steps

本地运行都报错

### 🚦 Expected Behavior

无

### 📝 Additional Information

无

Start by following the Ollama configuration guide at https://docs.nextchat.dev/models/ollama and reproduce the failure on Windows 11 with v2.15.1 using the official package. Trace the local Ollama request that produces “Failed to fetch” or “empty response from server”; done means a correctly configured local Ollama instance returns a response without either error.

Written by the indexing model from the issue text.