workerpool: Log when waiting for a thread
workerpool: Log when waiting for a thread

Reviewed-by: iustinp


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