fix ClientEngine.dbQuery without return
fix ClientEngine.dbQuery without return

rrrrrr8/vnpy,akeyong/vnpy,ujfjhz/vnpy,xcbat/vnpy,kernelmilowill/PDMQBACKTEST,ujfjhz/vnpy,wylwang/vnpy,rrrrrr8/vnpy,xcbat/vnpy,rrrrrr8/vnpy,msincenselee/vnpy,rrrrrr8/vnpy,wisfern/vnpy,Chemcy/vnpy,msincenselee/vnpy,wisfern/vnpy,harveywwu/vnpy,harveywwu/vnpy,wylwang/vnpy,akeyong/vnpy,akeyong/vnpy,xcbat/vnpy,jiangjinjinyxt/vnpy,wisfern/vnpy,akeyong/vnpy,harveywwu/vnpy,jiangjinjinyxt/vnpy,andrewchenshx/vnpy,jiangjinjinyxt/vnpy,wylwang/vnpy,ujfjhz/vnpy,Chemcy/vnpy,wylwang/vnpy,jiangjinjinyxt/vnpy,wylwang/vnpy,bigdig/vnpy,vnpy/vnpy,andrewchenshx/vnpy,kernelmilowill/PDMQBACKTEST,akeyong/vnpy,msincenselee/vnpy,harveywwu/vnpy,harveywwu/vnpy,rrrrrr8/vnpy,andrewchenshx/vnpy,andrewchenshx/vnpy,bigdig/vnpy,xcbat/vnpy,kernelmilowill/PDMQBACKTEST,wisfern/vnpy,vnpy/vnpy,xcbat/vnpy,ujfjhz/vnpy,rrrrrr8/vnpy,bigdig/vnpy,jiangjinjinyxt/vnpy,bigdig/vnpy,ujfjhz/vnpy,kernelmilowill/PDMQBACKTEST,andrewchenshx/vnpy,wisfern/vnpy,wisfern/vnpy,Chemcy/vnpy,kernelmilowill/PDMQBACKTEST,Chemcy/vnpy,msincenselee/vnpy,Chemcy/vnpy,harveywwu/vnpy