Comparison in shell is done with single to be portable

Author: neteler

grass-gis-test-docker/test.sh

@@ -4,7 +4,7 @@
 set -e
 
 # download North Carolina test location if the test needs the data and run tests
-if [ "$1" == "NC" ]
+if [ "$1" = "NC" ]
 then
   g.extension g.download.location
   g.download.location url=https://grass.osgeo.org/sampledata/north_carolina/nc_spm_full_v2alpha2.tar.gz path=/grassdb