Handle missing FIRST pages. Fixes #473.
Handle missing FIRST pages. Fixes #473.

Gives back an empty list to a Datafeed when the corresponding page is missing, and only logs a warning. Fixes case where missing pages caused an exception for iterating a None, causing datafeeds to return tens of thousands of times per day.

synth3tk/the-blue-alliance,fangeugene/the-blue-alliance,1fish2/the-blue-alliance,tsteward/the-blue-alliance,jaredhasenklein/the-blue-alliance,jaredhasenklein/the-blue-alliance,verycumbersome/the-blue-alliance,josephbisch/the-blue-alliance,bvisness/the-blue-alliance,josephbisch/the-blue-alliance,josephbisch/the-blue-alliance,bvisness/the-blue-alliance,tsteward/the-blue-alliance,phil-lopreiato/the-blue-alliance,josephbisch/the-blue-alliance,verycumbersome/the-blue-alliance,nwalters512/the-blue-alliance,bdaroz/the-blue-alliance,synth3tk/the-blue-alliance,nwalters512/the-blue-alliance,verycumbersome/the-blue-alliance,1fish2/the-blue-alliance,verycumbersome/the-blue-alliance,bdaroz/the-blue-alliance,synth3tk/the-blue-alliance,bdaroz/the-blue-alliance,fangeugene/the-blue-alliance,tsteward/the-blue-alliance,bdaroz/the-blue-alliance,bdaroz/the-blue-alliance,josephbisch/the-blue-alliance,jaredhasenklein/the-blue-alliance,1fish2/the-blue-alliance,bvisness/the-blue-alliance,tsteward/the-blue-alliance,nwalters512/the-blue-alliance,fangeugene/the-blue-alliance,bdaroz/the-blue-alliance,synth3tk/the-blue-alliance,jaredhasenklein/the-blue-alliance,josephbisch/the-blue-alliance,fangeugene/the-blue-alliance,jaredhasenklein/the-blue-alliance,nwalters512/the-blue-alliance,bvisness/the-blue-alliance,phil-lopreiato/the-blue-alliance,phil-lopreiato/the-blue-alliance,fangeugene/the-blue-alliance,the-blue-alliance/the-blue-alliance,tsteward/the-blue-alliance,phil-lopreiato/the-blue-alliance,tsteward/the-blue-alliance,1fish2/the-blue-alliance,the-blue-alliance/the-blue-alliance,the-blue-alliance/the-blue-alliance,phil-lopreiato/the-blue-alliance,jaredhasenklein/the-blue-alliance,verycumbersome/the-blue-alliance,synth3tk/the-blue-alliance,nwalters512/the-blue-alliance,nwalters512/the-blue-alliance,the-blue-alliance/the-blue-alliance,1fish2/the-blue-alliance,synth3tk/the-blue-alliance,bvisness/the-blue-alliance,1fish2/the-blue-alliance,bvisness/the-blue-alliance,verycumbersome/the-blue-alliance,phil-lopreiato/the-blue-alliance,fangeugene/the-blue-alliance,the-blue-alliance/the-blue-alliance,the-blue-alliance/the-blue-alliance