title: git-svn: how to change the svn username on dcommit?
body: <p>I cloned a SVN repository into a git repository using <code>git svn clone</code>. At that point in time, I did not have a username at that site and hence didn't use the <code>--username</code> option of <code>clone</code>. As I can now commit to the SVN repository with my new username, I would like to add that username. Without it, <code>dcommit</code> simply fails:</p>
  
  <pre><code>% LANG=C git svn dcommit 
  Committing to &lt;THE URL&gt; ...
  RA layer request failed: Server sent unexpected return value (405 Method Not Allowed) in response to MKACTIVITY request for '/svn/!svn/act/0ceca4c5-f7b4-4432-94be-0485559a6040' at /usr/lib/git-core/git-svn line 945.
  </code></pre>
  
  <p>Is there a way to tell git about a new username? The <a href="http://www.kernel.org/pub/software/scm/git/docs/git-svn.html" rel="noreferrer">git-svn manual</a> doesn't seem to help: adding a username is only allowed on <code>init</code> and <code>branch</code>. I don't know how git works with SVN internally, but I guess there should be a way to add a username afterwards.</p>
  
  <p>Note that I am using SVN over http.</p>