print right controller purpose string for measure-timeout circs

changes/string-for-measure-timeout-circs

@@ -0,0 +1,4 @@
+  o Minor bugfixes:
+    - When the controller is reporting the purpose of circuits that
+      didn't finish building before the circuit build timeout, it was
+      printing UNKNOWN_13. Now print EXPIRED. Bugfix on 0.2.2.14-alpha.

src/or/circuitlist.c

@@ -352,6 +352,8 @@ circuit_purpose_to_controller_string(uint8_t purpose)
 
     case CIRCUIT_PURPOSE_TESTING:
       return "TESTING";
+    case CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT:
+      return "EXPIRED";
     case CIRCUIT_PURPOSE_CONTROLLER:
       return "CONTROLLER";