[widgets][plotterparameterseditor] Use ValueError instead of Exception

logging.exception instead of logging.error
4 jobs for issue-278-plotterparam-default-value in 26 minutes and 29 seconds (queued for 1 second)
Status Name Job ID Coverage
  Build
passed build_linux_36 #204775
docker

00:11:38

90.0%
passed build_linux_37 #204776
docker

00:11:21

90.0%
passed build_macosx_36 #204773
macosx

00:26:29

90.0%
passed build_macosx_37 #204774
macosx

00:25:40

90.0%