skip Build-Depends scraping if apt-get is new enough

Starting in apt v1.1, `apt-get build-dep` accepts a path to a source package
as an argument, instead of just a package name.

gitlab-ci-git-buildpackage

@@ -15,7 +15,9 @@ if [[ ! -f $lockfile ]] ; then
     apt-get -qy dist-upgrade
 
     cd $CI_PROJECT_DIR
-    if ! apt-get -qy build-dep $CI_PROJECT_DIR; then
+    if dpkg --compare-versions `dpkg -s apt |sed -n 's,^Version: \(.*\),\1,p'` ge 1.1; then
+        apt-get -qy build-dep $CI_PROJECT_DIR
+    else
         # this is running on an older version, like jessie-backports
         export BUILD_DEPENDS=`sed 's/\s*|[^,]*,/,/g' debian/control | perl -ne 'next if /^#/; $p=(s/^Build-Depends:\s*/ / or (/^ / and $p)); s/,|\n|\([^)]+\)//mg; print if $p'`
         apt-get -qy install --no-install-recommends \