fix: baseURL not working in APITypePaLM (#317)

* fix: baseURL not working in APITypePaLM

* chore: use the same logic as claude

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Co-authored-by: JustSong <songquanpeng@foxmail.com>

controller/relay-text.go

@@ -140,6 +140,9 @@ func relayTextHelper(c *gin.Context, relayMode int) *OpenAIErrorWithStatusCode {
 		fullRequestURL += "?access_token=" + apiKey // TODO: access token expire in 30 days
 	case APITypePaLM:
 		fullRequestURL = "https://generativelanguage.googleapis.com/v1beta2/models/chat-bison-001:generateMessage"
+		if baseURL != "" {
+			fullRequestURL = fmt.Sprintf("%s/v1beta2/models/chat-bison-001:generateMessage", baseURL)
+		}
 		apiKey := c.Request.Header.Get("Authorization")
 		apiKey = strings.TrimPrefix(apiKey, "Bearer ")
 		fullRequestURL += "?key=" + apiKey