gdocs Preferences invalid cache

[unhammer]

cf. giellalt/lang-smj#109 (comment)
I kept getting a five year old preferences list for smj, Sjur gave me a tip to try localStorage.clear() in the various iframes and that fixed it.

$ time curl -sS  'https://api-giellalt.uit.no/preferences/grammar/smj' >/dev/null

real	0m0,150s
user	0m0,049s
sys	0m0,009s

The call to /preferences/ is fast; the cache could e.g. be updated on opening the plugin.