The BZ's description:
I have only one vault configured in the standalone.xml but I see following warning message in the server log file after login attempt (bindCredentials login module option uses a vaulted password):

09:10:58,854 WARN  [org.jboss.security] (http-/127.0.0.1:8080-1) PBOX000378: Attempt to create the second Security Vault [org.picketbox.plugins.vault.PicketBoxSecurityVault] is invalid. Only one Security Vault is supported. Change your configuration, please.

This issue is related to the previous fix for bz1055577, [1]. The problem needs to be fixed on EAP side in time of Security Subsystem configuration processing. Fix will be provided by bz1181457 [2].

[1] https://bugzilla.redhat.com/show_bug.cgi?id=1055577
[2] https://bugzilla.redhat.com/show_bug.cgi?id=1181457