changes: Use the first Tor version with CI coverage for the 29036 changes file

Otherwise, "make check-changes" will complain when we backport the change.

changes/bug29036

   o Minor bugfix (continuous integration):
     - Reset coverage state on disk after Travis CI has finished. This is being
       done to prevent future gcda file merge errors which causes the test suite
-      for the process subsystem to fail. Fixes bug 29036; bugfix on 0.4.0.1-alpha.
-
+      for the process subsystem to fail. The process subsystem was introduced
+      in 0.4.0.1-alpha. Fixes bug 29036; bugfix on 0.2.9.15.