feat: Improve image handling for Ollama channels

relay/channel/ollama/adaptor.go

@@ -46,7 +46,7 @@ func (a *Adaptor) ConvertRequest(c *gin.Context, info *relaycommon.RelayInfo, re
 	if request == nil {
 		return nil, errors.New("request is nil")
 	}
-	return requestOpenAI2Ollama(*request), nil
+	return requestOpenAI2Ollama(*request)
 }
 
 func (a *Adaptor) ConvertRerankRequest(c *gin.Context, relayMode int, request dto.RerankRequest) (any, error) {