submission script creates filenames that are too long

Using the python base64.urlsafe_b64encode() in the condor submission controller to create filenames for batch submission sometimes results in too long filenames and hence a crash:

IOError: [Errno 36] File name too long: '/afs/desy.de/user/b/bejaeger/xxl/af-atlas/2HWWAnalysis/HWWAnalysisCode/share/submissionWorkloadTemp/MTU1NDkwMzYyNV9DYWxjdWxhdGVCcmVha2Rvd25fYXNpbW92X2dyb3VwX0FUTEFTX0ZUX0VGRl9FaWdlbl9MaWdodF8wX3RoZW9fZ2dmX1FDRHNjYWxlX2dnSF9xbV90X3RoZW9fZ2dmX2dlbl9NR19BVExBU19FTF9FRkZfSURfQ29yclVuY2VydGFpbnR5X05QOV9BVExBU19NVU9OU19JRF9BVExBU19KRVJfRWZmZWN0aXZlTlBfM19BVExBU19GVF9FRkZfRWlnZW5fTGlnaF9ldGM=.sh'