force observer init for cases where initial value is undefined
force observer init for cases where initial value is undefined

cgvarela/ractive,JonDum/ractive,marcalexiei/ractive,pingjiang/ractive,JonDum/ractive,thomsbg/ractive,ractivejs/ractive,npmcomponent/RactiveJS-Ractive,ndimas/ractive,heavyk/ractive,magicdawn/ractive,squaredup/ractive,squaredup/ractive,Rich-Harris/ractive,p0lax/ractive,JonDum/ractive,heavyk/ractive,ISNIT0/ractive,aliprogrammer69/ractive,ractivejs/ractive,thomsbg/ractive,ISNIT0/ractive,marcalexiei/ractive,aliprogrammer69/ractive,thomsbg/ractive,ndimas/ractive,squaredup/ractive,p0lax/ractive,cgvarela/ractive,magicdawn/ractive,ndimas/ractive,Rich-Harris/ractive,aliprogrammer69/ractive,dyx/ractive,dyx/ractive,Rich-Harris/ractive,cgvarela/ractive,ractivejs/ractive,magicdawn/ractive,dyx/ractive,pingjiang/ractive,marcalexiei/ractive,pingjiang/ractive,heavyk/ractive,ISNIT0/ractive,npmcomponent/RactiveJS-Ractive