[app/explorer-v2,js][xs]: get rid of alert when no default drilldowns as annoying.
[app/explorer-v2,js][xs]: get rid of alert when no default drilldowns as annoying.

openspending/openspendingjs,RCGTDev/openspendingjs,openspending/openspendingjs-old,RCGTDev/openspendingjs,RCGTDev/openspendingjs,openspending/openspendingjs,openspending/openspendingjs-old,openspending/openspendingjs-old,openspending/openspendingjs,RCGTDev/openspendingjs,openspending/openspendingjs-old,openspending/openspendingjs