add fix

app.py

@@ -111,7 +111,7 @@ def main() -> None:
 
                     for line in re.split(r'(?<!\w\.\w.)(?<![A-Z][a-z]\.)(?<=\.|\?)\s', summary):
                         if line.find(".") != -1:
-                            line.replace("..", ".")
+                            line = line.replace("..", ".")
                             summary_sentences.append(line)
                 display_summary(summary_sentences)