wrap confluence attachment processing with a try-except block (#11503)

Prevents document loading from erroring out when an attachment is not
found at the url.

---------

Co-authored-by: Bagatur <baskaryan@gmail.com>

libs/langchain/langchain/document_loaders/confluence.py

@@ -541,6 +541,7 @@ class ConfluenceLoader(BaseLoader):
             media_type = attachment["metadata"]["mediaType"]
             absolute_url = self.base_url + attachment["_links"]["download"]
             title = attachment["title"]
+            try:
                 if media_type == "application/pdf":
                     text = title + self.process_pdf(absolute_url, ocr_languages)
                 elif (
@@ -561,6 +562,12 @@ class ConfluenceLoader(BaseLoader):
                 else:
                     continue
                 texts.append(text)
+            except requests.HTTPError as e:
+                if e.response.status_code == 404:
+                    print(f"Attachment not found at {absolute_url}")
+                    continue
+                else:
+                    raise
 
         return texts