Fix Error when adding a Drug
Fix Error when adding a Drug

After addition of a new drug , vm.newDrugDescription was set to null
causing an error . The App stop adding new drugs until to be reloaded
again. Value changed from zero to '' ( empty).

eshramchevskaya/AST,isp1r0/ANNE-stack,isp1r0/ANNE-stack,eshramchevskaya/AST,mchengal/ANNE-stack,fraserhore/ANNE-stack,crardin/nag,mchengal/ANNE-stack,isp1r0/ANNE-stack,eshramchevskaya/AST,crardin/nag,mchengal/ANNE-stack,crardin/nag,isp1r0/ANNE-stack,crardin/nag,eshramchevskaya/AST,fraserhore/ANNE-stack,fraserhore/ANNE-stack,fraserhore/ANNE-stack,mchengal/ANNE-stack