Make update and svn 1.7

Due to a change in the "svn info" output, the "make update" command has some issue with svn 1.7

With svn 1.7, the svn info command outputs an additional line for the working copy root path like this one:

svn17.patch (417 Bytes)

Looks good to me, committed as r142535. I don't actually have svn 1.7
to verify the behavior you describe, but the patch seems like the
right thing to do anyway to be more precise about what we're matching.

- David