update token field name

Author: dauglyon

src/main/java/us/kbase/auth2/lib/storage/mongo/Fields.java

@@ -138,7 +138,7 @@ public class Fields {
 	/** A value for a custom context key / value pair. */
 	public static final String TOKEN_CUSTOM_VALUE = "v";
 	/** Whether the token was created with multi-factor authentication. */
-	public static final String TOKEN_MFA_AUTHENTICATED = "mfaauth";
+	public static final String TOKEN_MFA_AUTHENTICATED = "mfa";
 
 	/* ************************
 	 * temporary session data fields