Add enablePasswordDB: true for Dex (#182)

`{!c.EnablePasswordDB && len(c.StaticPasswords) != 0, "cannot specify static passwords without enabling password db"},`

manuscript/ha-docker-swarm/traefik-forward-auth/dex-static.md

@@ -35,6 +35,8 @@ staticClients:
   name: 'example.com'
   secret: bar
 
+enablePasswordDB: true
+
 staticPasswords:
 - email: "admin@example.com"
   # bcrypt hash of the string "password"