Fix default cipher
Fix default cipher

Signed-off-by: Woody Gilk <0bbbba7770b1bbf11a4ba4287fb5f0d87d17df25@wingsc.com>

candeira/git-encrypt,miraclhq/git-encrypt,almendro/git-encrypt,denis-vilyuzhanin/git-encrypt,janzhou/git-encrypt,kinnalru/gitcrypt,marcind/git-encrypt,sergey-ob/git-encrypt,kinnalru/gitcrypt,spector-in-london/git-encrypt