You can clone with
HTTPS or Subversion.
Reported in forum:
It's no longer working since Piwik 1.10 was released.
Problem is I do enable subtables only if Piwik version is > 1.8.4
But the app is thinking that 1.10.1 is older than 1.8.4. Cause app interprets version "1.10.*" as version "1.1.0"