Add saveguard not to include 0 in a scale for logarithmic axes Including 0 or allowing negative values triggers a bug in the jfreechart logarithmic axis code that causes values < 1 to be drawn in carthesic coordinates. Fixes: flys/issue12345

<?xml version="1.0" encoding="UTF-8" ?>
<datacage>
    <user>SA</user>
    <password/>
    <driver>org.h2.Driver</driver>
    <url>jdbc:h2:${artifacts.config.dir}/../datacagedb/datacage</url>
</datacage>