Update client-p4.asc

 - Change 'ben' to 'john' to fit the rest of the example.

Author: JoshuaWebb

book/09-git-and-other-scms/sections/client-p4.asc

@@ -193,7 +193,7 @@ We'll assume we've mapped in the ``Jam'' project using a configuration file as s
 $ git clone https://10.0.1.254/Jam
 Cloning into 'Jam'...
 Username for 'https://10.0.1.254': john
-Password for 'https://ben@10.0.1.254':
+Password for 'https://john@10.0.1.254':
 remote: Counting objects: 2070, done.
 remote: Compressing objects: 100% (1704/1704), done.
 Receiving objects: 100% (2070/2070), 1.21 MiB | 0 bytes/s, done.