fix ChatCompletion and ChatCompletionChunk object string not compatible with...

fix ChatCompletion and ChatCompletionChunk object string not compatible with standard openai api (#2089)
Co-authored-by: sunxichen <sun.xc@digitalcnzz.com>

router/src/lib.rs

@@ -570,7 +570,7 @@ impl ChatCompletion {
         };
         Self {
             id: String::new(),
-            object: "text_completion".into(),
+            object: "chat.completion".into(),
             created,
             model,
             system_fingerprint,
@@ -682,7 +682,7 @@ impl ChatCompletionChunk {
         };
         Self {
             id: String::new(),
-            object: "text_completion".to_string(),
+            object: "chat.completion.chunk".to_string(),
             created,
             model,
             system_fingerprint,