null check instead of empty check
null check instead of empty check

As suggested by @psychoticmeow, use the null comparison
in order to let 0 be a valid default value.

NikoMostWanted/symphony-2,avanteweb/symphony-2,brendo/symphony-2,twiro/symphony-2,twiro/symphony-2,alexnantel88/symphony-2,bauhouse/sym-todo-list,jonmifsud/symphony-2,jensscherbl/symphony,johnpuddephatt/symphony-2,mazedigital/jcilearn,johnpuddephatt/symphony-2,DeuxHuitHuit/symphony-2,roshinebagha/Symphony-Test,symphonycms/symphony-2,DavidForster/symphony-2,DavidForster/symphony-2,roshinebagha/Symphony-Test,blaXXabla/projet_test_symphony,blaXXabla/projet_test_symphony,BloodBrother/symphony-2,michael-e/symphony-2,jensscherbl/symphony,michael-e/symphony-2,NikoMostWanted/symphony-2,jurajkapsz/symphony-2,bauhouse/sym-todo-list,jurajkapsz/symphony-2,symphonycms/symphony-2,mazedigital/jcilearn,DeuxHuitHuit/symphony-2,mazedigital/jcilearn,BloodBrother/symphony-2,ljonka/symphony-2,avanteweb/symphony-2,alexnantel88/symphony-2,jonmifsud/symphony-2,ljonka/symphony-2,brendo/symphony-2