Update deckgrid.js
Update deckgrid.js

It seems like this should be an OR, not an AND.  If rule.cssRules is undefined, we should always exit, correct?  Otherwise, the next statement, i = rule.cssRules.length - 1, throws an error.
famoraes/angular-deckgrid,sandybemonkey/angular-deckgrid,lithiumtech/angular-deckgrid,kgislsompo/angular-deckgrid,sunshineo/angular-deckgrid,itxd/angular-deckgrid,ganquan0910/angular-deckgrid,leonardobarrientosc/angular-deckgrid,VolosSoftware/angular-deckgrid,iDay/angular-deckgrid,akoenig/angular-deckgrid,qq645381995/angular-deckgrid,shemetov-info/angular-deckgrid