fixup! feat(config): add option to set token from file

Author: nydragon

config.toml

@@ -1,9 +1,9 @@
 [server]
 address = "https://paste.example.com"
 #auth_token = ""
-#auth_token_file = "~/example/auth-token"
+#auth_token_file = "~/example/auth-token" # File should contain a string, leading and trailing whitespace will be removed
 #delete_token = ""
-#delete_token_file = "~/example/delete-token"
+#delete_token_file = "~/example/delete-token" # File should contain a string, leading and trailing whitespace will be removed
 
 [paste]
 oneshot = false