doRefreshAndRender() returned at once when a refresh was already running. An
import asks for a refresh after its address scan, so the addresses the scan
found showed 0.0000 until the next ten-second refresh.
A request made while a refresh runs now sets a flag. One more refresh runs
once the running one ends. Several requests in that time lead to one more
refresh, not several. A tick of the ten-second timer during a refresh counts
as such a request too.
Model: opus-5-5
