local_hub: put a lock in when restarting sage server
local_hub: put a lock in when restarting sage server

tscholl2/smc,sagemathinc/smc,DrXyzzy/smc,sagemathinc/smc,sagemathinc/smc,sagemathinc/smc,DrXyzzy/smc,tscholl2/smc,tscholl2/smc,tscholl2/smc,DrXyzzy/smc,tscholl2/smc,DrXyzzy/smc