Update app.py

app.py

@@ -72,7 +72,7 @@ def extract_text_from_docx(docx_data, clean=True):
 def extract_text_from_pptx(pptx_data, clean=True):
     """Extracts text from PPT files."""
     text = u''
-    zipf = zipfile.ZipFile(io.BytesIO(docx_data))
+    zipf = zipfile.ZipFile(io.BytesIO(pptx_data))
 
     filelist = zipf.namelist()