Check for 0.2.4.8, not 0.2.4.7, to determine EXTEND2 support

Fixes bug 8464; bugfix on b2863739 in 0.2.4.8-alpha

changes/bug8464

@@ -0,0 +1,5 @@
+  o Minor bugfixes:
+    - Correct our check for which versions of Tor support the EXTEND2
+      cell.  We had been willing to send it to Tor 0.2.4.7-alpha and
+      later, when support was really added in version 0.2.4.8-alpha.
+      Fixes bug 8464; bugfix on 0.2.4.8-alpha.

src/or/routerparse.c

@@ -1953,7 +1953,7 @@ routerstatus_parse_entry_from_string(memarea_t *area,
       rs->version_supports_optimistic_data =
         tor_version_as_new_as(tok->args[0], "0.2.3.1-alpha");
       rs->version_supports_extend2_cells =
-        tor_version_as_new_as(tok->args[0], "0.2.4.7-alpha");
+        tor_version_as_new_as(tok->args[0], "0.2.4.8-alpha");
     }
     if (vote_rs) {
       vote_rs->version = tor_strdup(tok->args[0]);