-debug true doesn't work with reduce

[dmehra]

When the program contains reduce, reading with -debug true does not return the query URL, and does something funny instead.

juttle> read opentsdb -from :2016-01-01: -name 'dm.my.test' | reduce sum(value)
┌───────────────────────────┐
│ sum                       │
├───────────────────────────┤
│ 41.002000000094995        │
└───────────────────────────┘
juttle> read opentsdb -from :2016-01-01: -name 'dm.my.test' -debug true | reduce sum(value)
┌──────────┐
│ sum      │
├──────────┤
│ 0        │
└──────────┘

When looking at this, also consider that the plan for debug logging going forward is to support DEBUG=* and print the query to the log, rather than returning it as data, see the adapter unification issue juttle/juttle#84.