Correct dashes for forecast

discovered with this config

```
location:Stockholm,SE
units:metric
symbols:true
fetch_cmd:/usr/bin/curl -s
daylight:true
background:\033[0m
text:\033[30;1m
data:\033[32;1m
delimiter:\t
dashes:\n
greeting_text:\n
wind_text:Wind  
forecast:5
```

PS: minor improvements in the first 2 commits