Prefer single-quotes where \n is used

bin/dissect_url

@@ -20,7 +20,7 @@ main() {
         do
             if [[ -z "$url" ]]; then exit 0; fi
             i=`expr $i + 1`
-            printf "=== url %02d =============================================\n" $i
+            printf '=== url %02d =============================================\n' $i
             dissect "$url"
         done
     fi