Better to check the return code of the file indeed there than otherwi…

…se (#4100)

conans/client/rest/uploader_downloader.py

@@ -25,7 +25,7 @@ def upload(self, url, abs_path, auth=None, dedup=False, retry=1, retry_wait=0, h
                 dedup_headers.update(headers)
             response = self.requester.put(url, data="", verify=self.verify, headers=dedup_headers,
                                           auth=auth)
-            if response.status_code != 404:
+            if response.status_code == 201:  # Artifactory returns 201 if the file is there
                 return response
 
         headers = headers or {}