Fix version number in changes/bug11296

changes/bug11296

@@ -1,3 +1,3 @@
   o Minor bugfixes:
     - Allow tor-fw-helper to build again by adding src/ext to its
-      CPPFLAGS. Fixes bug 11296; bugfix on 0.2.5.4-alpha.
+      CPPFLAGS. Fixes bug 11296; bugfix on 0.2.5.3-alpha.