Add changes file for bug2195.

changes/bug2195

@@ -0,0 +1,7 @@
+  o Minor bugfixes
+    - Publish a router descriptor even if generating an extra-info
+      descriptor fails.  Previously we would not publish a router
+      descriptor without an extra-info descriptor; this can cause fast
+      exit relays collecting exit-port statistics to drop from the
+      consensus.  Bugfix on 0.1.2.9-rc; fixes bug 2195.
+