get_evbf() is not producing the correct indicator results

[ernestguevarra]

For example:

df <- within(iycfData, {
  evbf <- get_evbf(q4 = child_bf, age = calc_age_months)
})

table(df$evbf)

which produces:

  0   1 
  8 145 

when checking manually:

with(df, table(calc_age_months < 24, child_bf))

which produces:

     child_bf
          0   1 999
  FALSE   0   0   0
  TRUE    7 145   1

get_evbf() seems to be counting the one record that reports a 999 value for child_bf