Fix: The data set created by API call failed to parse after uploading the file. (#8657)

### What problem does this PR solve?

https://github.com/infiniflow/ragflow/issues/8656

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

rag/svr/task_executor.py

@@ -445,7 +445,10 @@ async def embedding(docs, mdl, parser_config=None, callback=None):
         tk_count += c
         callback(prog=0.7 + 0.2 * (i + 1) / len(cnts), msg="")
     cnts = cnts_
-    title_w = float(parser_config.get("filename_embd_weight", 0.1))
+    filename_embd_weight = parser_config.get("filename_embd_weight", 0.1) # due to the db support none value
+    if not filename_embd_weight:
+        filename_embd_weight = 0.1
+    title_w = float(filename_embd_weight)
     vects = (title_w * tts + (1 - title_w) *
              cnts) if len(tts) == len(cnts) else cnts