[bcp][worker] Add missing variable initialisation for optional argument

4 jobs for fix_bcpworker_script in 16 minutes and 11 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Build
passed #190296
docker-build
build_linux_36

00:13:37

64.0%
passed #190297
docker-build
build_linux_37

00:13:38

64.0%
passed #190294
macosx
build_macosx_36

00:16:10

64.0%
passed #190295
macosx
build_macosx_37

00:16:11

64.0%