fix: allow openai list message format

backend/open_webui/apps/ollama/main.py

@@ -817,7 +817,7 @@ class OpenAIChatMessageContent(BaseModel):
 
 class OpenAIChatMessage(BaseModel):
     role: str
-    content: Union[str, OpenAIChatMessageContent]
+    content: Union[str, list[OpenAIChatMessageContent]]
 
     model_config = ConfigDict(extra="allow")
 
@@ -836,7 +836,15 @@ async def generate_openai_chat_completion(
     url_idx: Optional[int] = None,
     user=Depends(get_verified_user),
 ):
-    completion_form = OpenAIChatCompletionForm(**form_data)
+    try:
+        completion_form = OpenAIChatCompletionForm(**form_data)
+    except Exception as e:
+        log.exception(e)
+        raise HTTPException(
+            status_code=400,
+            detail=str(e),
+        )
+
     payload = {**completion_form.model_dump(exclude_none=True, exclude=["metadata"])}
     if "metadata" in payload:
         del payload["metadata"]