GUACAMOLE-394: Cover both main object ID and "start_date" columns with an index for sake of correlated MAX(start_date) history queries.

extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-postgresql/schema/001-create-schema.sql

@@ -438,6 +438,9 @@ CREATE INDEX guacamole_connection_history_start_date
 CREATE INDEX guacamole_connection_history_end_date
     ON guacamole_connection_history(end_date);
 
+CREATE INDEX guacamole_connection_history_connection_id_start_date
+    ON guacamole_connection_history(connection_id, start_date);
+
 --
 -- User login/logout history
 --
@@ -468,6 +471,9 @@ CREATE INDEX guacamole_user_history_start_date
 CREATE INDEX guacamole_user_history_end_date
     ON guacamole_user_history(end_date);
 
+CREATE INDEX guacamole_user_history_user_id_start_date
+    ON guacamole_user_history(user_id, start_date);
+
 --
 -- User password history
 --