petascope_insertdemo.sh test for coverage always fails

[abeccati]

With the changeset 58ab1438 modification I always get "already inserted" when testing for the presence of mean_summer_airtemp into petascope.

Changing the test to:
if [ "$id" == \(0\ rows\) ] ; then

works on my English-language setup, inserting the demo as needed

The wildcard expansions used seems not a reliable way of testing, probably using substring to test only the first three characters would work