Add index to log table (time stamp column).

sql/database-create.sql

@@ -1225,7 +1225,8 @@ CREATE TABLE log (
   relevant tinyint(1) NOT NULL default '0',
   mesg text NOT NULL,
   PRIMARY KEY  (seq),
-  KEY session (session)
+  KEY session (session),
+  KEY stamp (stamp)
 ) TYPE=MyISAM;
 
 --

sql/database-migrate.txt

@@ -3279,3 +3279,7 @@ last_net_act,last_cpu_act,last_ext_act);
 
       alter table virt_node_motelog drop primary key;
       alter table virt_node_motelog add primary key(pid,eid,vname,logfileid);
+
+4.48: Add index to log table.
+
+      alter table log add key stamp (stamp);