qubes module: Typo fix
qubes module: Typo fix

This commit fixes a typo, where the exception type DontSave was used,
even though the name of the function dontsave was intended.

QubesOS/qubes-core-admin,QubesOS/qubes-core-admin,marmarek/qubes-core-admin,QubesOS/qubes-core-admin,marmarek/qubes-core-admin,marmarek/qubes-core-admin