test-pkg: filter empty lines and comments in CSV file

In preparation for the addition of comments in the CSV file listing
toolchain configurations, we filter out such lines when reading the
CSV file in utils/test-pkg.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

utils/test-pkg

@@ -54,7 +54,7 @@ main() {
     # Extract the URLs of the toolchains; drop internal toolchains
     # E.g.: http://server/path/to/name.config,arch,libc
     #  -->  http://server/path/to/name.config
-    toolchains=($(sed -r -e 's/,.*//; /internal/d;' "${toolchains_csv}" \
+    toolchains=($(sed -r -e 's/,.*//; /internal/d; /^#/d; /^$/d;' "${toolchains_csv}" \
                   |if [ ${random} -gt 0 ]; then \
                       sort -R |head -n ${random}
                    else