The default single user slug `bbp_get_user_slug()` is `users`, not `user`

[netweb]

The default value of bbp_get_user_slug() should be users, not user, see ​src/includes/core/options.php#L615

The bbp_get_default_options() function defines the default as users, see ​src/includes/core/options.php#L82

In a scenario where bbPress options have not been saved as ​happened recently with the international forums rollout this will cause the single user slug to be user and not users. Resaving bbPress' options restores users as the single user slug.

Edit: Originally reported in ​#meta1868 #18

[netweb]

In 6078:

Options: Set the default value of bbp_get_user_slug() to users

This changeset updates the default single user slug from user to users. The bbp_get_default_options() function defines the default as users and this is used when installing and activating bbPress. This fixes a scenario where bbPress options have not been saved which would cause the single user slug to use the unexpected slug user rather than users.

Props ocean90.
Fixes #2983

[netweb]

In 6080:

Tests: Following r6078 update tests in ::BBP_Tests_Users_Template_User to use single user slug users

See #2983