docs: update example for borg create -v --stats (use iso datetime format), fixes #663

the code already was updated after 1.0.0rc1, but not the quickstart docs.

docs/quickstart.rst

@@ -56,8 +56,9 @@ A step by step example
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     Archive name: Tuesday
     Archive fingerprint: bd31004d58f51ea06ff735d2e5ac49376901b21d58035f8fb05dbf866566e3c2
-    Start time: Tue Feb 16 18:15:11 2016
-    End time: Mon Feb 16 18:15:11 2016
+    Time (start): Tue, 2016-02-16 18:15:11
+    Time (end):   Tue, 2016-02-16 18:15:11
+
     Duration: 0.19 seconds
     Number of files: 127
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