Fix a memleak when fetching descriptors for bridges in ExcludeNodes.

changes/bug4383

@@ -0,0 +1,5 @@
+  o Minor bugfixes:
+    - Fix a memleak in launch_direct_bridge_descriptor_fetch() that
+      occured when a client tried to fetch a descriptor for a bridge
+      in ExcludeNodes. Fixes #4383; bugfix on 0.2.2.25-alpha.
+

src/or/circuitbuild.c

@@ -4670,7 +4670,6 @@ launch_direct_bridge_descriptor_fetch(bridge_info_t *bridge)
       DIR_PURPOSE_FETCH_SERVERDESC))
     return; /* it's already on the way */
 
-  address = tor_dup_addr(&bridge->addr);
   if (routerset_contains_bridge(options->ExcludeNodes, bridge)) {
     download_status_mark_impossible(&bridge->fetch_status);
     log_warn(LD_APP, "Not using bridge at %s: it is in ExcludeNodes.",
@@ -4678,6 +4677,8 @@ launch_direct_bridge_descriptor_fetch(bridge_info_t *bridge)
     return;
   }
 
+  address = tor_dup_addr(&bridge->addr);
+
   directory_initiate_command(address, &bridge->addr,
                              bridge->port, 0,
                              0, /* does not matter */