Update app.py

app.py

@@ -55,7 +55,7 @@ def read_file_content(file):
     elif file.type == "application/xml" or file.type == "text/xml":
         tree = ET.parse(file)
         root = tree.getroot()
-        return ElementTree.tostring(root, encoding='unicode')
+        return ET.tostring(root, encoding='unicode')
     elif file.type == "text/plain":
         return file.getvalue().decode()
     else: