Mainloop: avoid calculating timeout every time
Mainloop: avoid calculating timeout every time

set timeout_needs_update to False after calculating the timeout.

Reviewed-by: imsnah


ganeti-github-testing/ganeti-test-1,leshchevds/ganeti,yiannist/ganeti,apyrgio/ganeti,mbakke/ganeti,apyrgio/ganeti,andir/ganeti,dimara/ganeti,mbakke/ganeti,ganeti/ganeti,dimara/ganeti,leshchevds/ganeti,andir/ganeti,ganeti/ganeti,grnet/snf-ganeti,andir/ganeti,apyrgio/snf-ganeti,leshchevds/ganeti,yiannist/ganeti,yiannist/ganeti,onponomarev/ganeti,apyrgio/snf-ganeti,ganeti/ganeti,mbakke/ganeti,bitemyapp/ganeti,bitemyapp/ganeti,ganeti-github-testing/ganeti-test-1,onponomarev/ganeti,grnet/snf-ganeti