[exchange] Exchange rate is 1

[Stefano Rivera]

18:03 <tumbleweed> exchange 1 hrk for zar
18:03 <tibid> 1 HRK (Croatia Kuna) = 1.00 ZAR (South Africa Rand) (Last trade rate: 1.00, Bid: N/A, Ask: N/A)
18:03 <tumbleweed> exchange 1 hrk for zar
18:03 <tibid> 1 HRK (Croatia Kuna) = 1.31 ZAR (South Africa Rand) (Last trade rate: 1.3102, Bid: 1.3054, Ask: 1.3151)

Some more digging shows that Yahoo returns
1.00,N/A,N/A
for these bogus results, so maybe we should look for that and retry (ICK)

[Stefano Rivera (stefanor)]

Not seeing this any more. If it turns up again, we can detect it.