make regexp a bit more forgiving

vouchers.sh

@@ -8,7 +8,7 @@ function gendot(){
   echo "subgraph {";
   wget -q -O - https://pad.stratum0.org/p/35c3vouchers/export/txt |
     awk '/^\*[0-9]+\. Fertig/{f=1;next} /^\*[0-9]+/{f=0} !/^\s+1\. /{next} f{print tolower($0)}'|
-    sed -E -e "s/^\s*[0-9]+.\s+([^, _]+).*an ([^, _]+).*,\s+([0-9]{2})\.([0-9]{2})\.[0-9]{4}\s*$/\"\\1\" -> \"\\2\" \nsubgraph cluster_\\3\\4 {margin=10;label=\"\\3.\\4.     \"; pencolor=transparent; labeljust=l; \"\\2\"}/" |
+    sed -E -e "s/^\s*[0-9]+.\s+([^, _]+).*an\s+([^, _]+).*,\s+([0-9]{2})\.([0-9]{2})\.[0-9]{2,4}\s*$/\"\\1\" -> \"\\2\" \nsubgraph cluster_\\3\\4 {margin=10;label=\"\\3.\\4.     \"; pencolor=transparent; labeljust=l; \"\\2\"}/" |
     sed -E -s "s/(.*)\"xxx(.*)xxx\"(.*)/\\1 \"\\2\" \\3 \n\"\\2\" [shape=underline]/";
   echo "}}")
 }