fix: skip reasoning tag preceded by text

Author: Algorithm5838

backend/open_webui/utils/middleware.py

@@ -3638,6 +3638,10 @@ def set_last_text(out, text):
                             before_tag = item_text[: match.start()]
                             after_tag = item_text[match.end() :]
 
+                            # Tag in prose text, skip it.
+                            if before_tag.strip():
+                                continue
+
                             # Keep only text before the tag in the message
                             set_last_text(output, before_tag)