Command line in web app should prepend option values starting with `-` with `./`

[SebastianSimon]

E.g. entering -quality in backupDir will show the “Equivalent command line” as

./fixfx.sh -b '-quality'

which will actually be interpreted as

./fixfx.sh -b -q -u -a -l -i -t -y

potentially triggering undesirable options and throwing an error because -b is missing a value.

It should be

./fixfx.sh -b './-quality'

instead.