adblock: update to 1.5.4

Apply adblock updates 1.5.3-1.5.4

Signed-off-by: Hannu Nyman <hannu.nyman@iki.fi>

Original commit messages:

adblock: update 1.5.3
* make wget check more flexible,
  fix for broken wget package installations

adblock: bugfix 1.5.4
* CC/uclient-fetch compatibility fix

net/adblock/files/adblock-update.sh

@@ -41,6 +41,8 @@ f_envcheck
 
 # main loop for all block list sources
 #
+f_log "use '${adb_fetch}' for list downloads"
+
 for src_name in ${adb_sources}
 do
     # check disabled sources
@@ -83,7 +85,8 @@ do
     if [ "${src_name}" = "blacklist" ]
     then
         url_time="$(date -r "${url}")"
-    else
+    elif [ -n "${response_parm}" ]
+    then
         url_time="$(${adb_fetch} ${fetch_parm} ${response_parm} "${url}" 2>&1 | awk '$0 ~ /Last-Modified/ {printf substr($0,18)}')"
     fi
     if [ -z "${url_time}" ]