Double structure with forestry product reporting in demand()

[bodirsky]

Demand for forestry products is calculated twice in the model; one is not used, and in postprocessing overwritten by the second version of the calculation. This should be cleaned up in gams, linking forestry demand in materail demand or bioenergy demand

warning("Double structure for forestry products. Estimates in material demand and supply chain losses are overwritten")
out[, , forestry_products] <- 0
out[, , forestry_products][,,"other_util"] <- forestry

[tscheypidi]

the warning has now been converted to a comment to avoid spamming the log file with it. The problem itself obviously still persists.