Center the map

webapp_post.py

@@ -2163,6 +2163,8 @@ def individual_post_as_html(signing_priv_key_pem: str,
                     html_open_street_map(location_str,
                                          bounding_box_degrees,
                                          translate)
+                if map_str:
+                    map_str = '<center>\n' + map_str + '</center>\n'
 
     if is_muted:
         content_str = ''