Simplest fix to bug2402: do not include SVN versions

When we stopped using svn, 0.2.1.x lost the ability to notice its svn
revision and report it in the version number.  However, it kept
looking at the micro-revision.i file... so if you switched to master,
built tor, then switched to 0.2.1.x, you'd get a micro-revision.i file
from master reported as an SVN tag.  This patch takes out the "include
the svn tag" logic entirely.

Bugfix on 0.2.1.15-rc; fixes bug 2402.