Do not print FTL update check details on pihole -up (#5800)

advanced/Scripts/update.sh

@@ -144,7 +144,7 @@ main() {
     local binary
     binary="pihole-FTL${funcOutput##*pihole-FTL}" #binary name will be the last line of the output of get_binary_name (it always begins with pihole-FTL)
 
-    if FTLcheckUpdate "${binary}"; then
+    if FTLcheckUpdate "${binary}" &>/dev/null; then
         FTL_update=true
         echo -e "  ${INFO} FTL:\\t\\t${COL_YELLOW}update available${COL_NC}"
     else