Change error code to 500 when user create a conference but could not retrieve...

Change error code to 500 when user create a conference but could not retrieve it at the end of the process

flexisipccmp/LinphoneSDKManager/LinphoneCoreManager.py

@@ -333,8 +333,8 @@ class SDKCoreManager:
             xconIDReturn: str = str(creationConferenceInfo.ccmp_uri)
             conference = self._core.find_conference_information_from_ccmp_uri(xconIDReturn)
             if not conference:
-                logger.warning(f"Could not find conference for URI '{xconIDReturn}'")
-                raise HTTPException(detail=f"Could not find conference for URI '{xconIDReturn}'", status_code=404)
+                logger.warning(f"Could not find conference after creation with URI '{xconIDReturn}'")
+                raise HTTPException(detail=f"Could not find conference after creation with URI '{xconIDReturn}'", status_code=500)
             conferenceURI = str(conference.uri.as_string_uri_only())
             confIDReturn: str = xconIDReturn
             subject: str = str(conference.subject)