URL encode '+' characters in package names, or else we get Forbidden.

Changelog: Fix broken download of packages when `*_VERSION` are set to
`master`.

Signed-off-by: Kristian Amlie <kristian.amlie@northern.tech>

modules/deb.sh

@@ -47,7 +47,8 @@ function deb_from_repo_dist_get()  {
     fi
 
     local -r filename=$(basename $deb_package_path)
-    run_and_log_cmd "wget -Nq ${repo_url}/${deb_package_path} -P ${download_dir}"
+    local -r deb_package_url=$(echo ${repo_url}/${deb_package_path} | sed 's/+/%2B/g')
+    run_and_log_cmd "wget -Nq ${deb_package_url} -P ${download_dir}"
 
     rm -f /tmp/Packages
     log_info "Successfully downloaded ${filename}"