Fix minor docstring typo
Fix minor docstring typo

Signed-off-by: Stephen Shirley <f872caad177d67bbe18c119d0505f2d3caa02af3@google.com>
Reviewed-by: Iustin Pop <acf83a5274f31a43af6b914614365999469c1a31@google.com>

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