Revert "[jenkins] - use a new method to determine the branch name by …

…ignoring the pr ref_spec - thx to theuni for figuring that out"

This reverts commit afb5a69.

It resulted in "undefined" branch name. Stick with the old method until someone decides its not working for all cases. Sry TheUni - but theory proved wrong ... ;)

tools/buildsteps/defaultenv

@@ -119,7 +119,7 @@ function getBuildRevDateStr ()
   if [ "$?" == "0" ]
   then
     #fetch the first branch containing head
-    revStr=$revStr"-"`git name-rev --ref=refs/heads/* --name-only HEAD | head -n1 | awk '{gsub(".*/","");print $1}'`
+    revStr=$revStr"-"`git branch -r --contains HEAD | sed "/origin\/pr\//d" | head -n1 | awk '{gsub(".*/","");print $1}'`
     if [ "$?" == "0" ]
     then
       echo $revStr