try restore double-colon in kdf option

Author: jaromil

tomb

@@ -3143,7 +3143,7 @@ main() {
 
 	# -o in forge and lock is used to pass an alternate cipher.
 
-	subcommands_opts[forge]="-ignore-swap k: -kdf: -kdfiter: -kdfmem: -kdfpar: o: -tomb-pwd: -use-random r: R: -sphx-host: -sphx-user: "
+	subcommands_opts[forge]="-ignore-swap k: -kdf:: -kdfiter: -kdfmem: -kdfpar: o: -tomb-pwd: -use-random r: R: -sphx-host: -sphx-user: "
 	subcommands_opts[dig]="-ignore-swap s: -size=s "
 	subcommands_opts[lock]="-ignore-swap k: -kdf: -kdftype: -kdfmem: o: -tomb-pwd: r: R: -sphx-host: -sphx-user: -filesystem: "
 	subcommands_opts[setkey]="k: -ignore-swap -kdf: -kdftype: -kdfmem: -tomb-old-pwd: -tomb-pwd: r: R: -sphx-host: -sphx-user: "