The two <script src="{{ url_for(...) }}"> lines for the sync scripts
had Unicode smart-quotes (' / ') instead of ASCII apostrophes —
left over from a copy-paste at some point. Jinja's tokenizer hit the
first one and raised TemplateSyntaxError, so /settings returned a
500. Replaced with ASCII quotes and added the missing ?v=ASSET_VERSION
cache-buster the other static URLs already use.
Giorgio Gilestro
dbb14340db