[securityguide] add recommandation

[Fabian Affolter]

commit a7b06bdc34a327d4fd01308cabc2ff4a2b0828c2
Author: Fabian Affolter <fab at fedoraproject.org>
Date:   Sat Oct 4 10:07:34 2014 +0200

    add recommandation

 en-US/Yubikey.xml |    9 ++++++---
 1 files changed, 6 insertions(+), 3 deletions(-)
---
diff --git a/en-US/Yubikey.xml b/en-US/Yubikey.xml
index 6f6d9de..3262a56 100644
--- a/en-US/Yubikey.xml
+++ b/en-US/Yubikey.xml
@@ -18,7 +18,10 @@
 			<procedure>
 				<step>
 					<para>
-					Install <package>pam_yubico</package>
+					Install <package>pam_yubico</package> as root.
+					</para>
+					<para>
+						<command>yum install pam_yubico</command>
 					</para>
 				</step>
 				<step>
@@ -26,7 +29,7 @@
 					For two factor authentication open <filename>/etc/pam.d/gdm-password</filename> and locate the following line:
 					</para>
 					<para>
-						<command>auth        substack      password-auth </command>	
+						<command>auth        substack      password-auth </command>
 					</para>
 					<para>
 					In a new line after this add:
@@ -37,7 +40,7 @@
 				</step>
 				<step>
 					<para>
-					To simple use the yubikey token without your password remove the first line from the step above and replace it with the second.
+					To simple use the yubikey token without your password remove the first line from the step above and replace it with the second. It's not recommanded to use the yubikey without a password.  
 					</para>
 				</step>
 				<step>