Enable functional testing for a gzipped config

Refers to #80

.github/workflows/functional_test.yml

@@ -81,7 +81,7 @@ jobs:
         echo "l1tf=off mds=full randomize_kstack_offset=on iommu.passthrough=0" > ./cmdline_example
         cat ./cmdline_example
         CONFIG_DIR=`find . -name config_files`
-        KCONFIGS=`find $CONFIG_DIR -type f | grep "\.config"`
+        KCONFIGS=`find $CONFIG_DIR -type f | grep -e "\.config" -e "\.gz"`
         COUNT=0
         for C in $KCONFIGS
         do