fix: key flag id for KSK, fix format (#2063)
fix: key flag id for KSK, fix format (#2063)

as mentioned (https://github.com/mail-in-a-box/mailinabox/pull/2033#issuecomment-976365087) KSK is 257, not 256
mail-in-a-box/mailinabox,mail-in-a-box/mailinabox,mail-in-a-box/mailinabox,mail-in-a-box/mailinabox