feat: Fill thoughtSignature only for Gemini/Vertex channels using the OpenAI format

relay/channel/vertex/adaptor.go

@@ -296,7 +296,7 @@ func (a *Adaptor) ConvertOpenAIRequest(c *gin.Context, info *relaycommon.RelayIn
 		info.UpstreamModelName = claudeReq.Model
 		return vertexClaudeReq, nil
 	} else if a.RequestMode == RequestModeGemini {
-		geminiRequest, err := gemini.CovertGemini2OpenAI(c, *request, info)
+		geminiRequest, err := gemini.CovertOpenAI2Gemini(c, *request, info)
 		if err != nil {
 			return nil, err
 		}