Clean up handlers has from response after data processing is done

In most cases this should not leave any handlers on the object, but the
user might have injected a 'response_done' or 'response_redirect'
handler and we actually want those to stay around until those phases
arrives.

lib/LWP/Protocol.pm

@@ -161,9 +161,12 @@ sub collect
             }
         }
     };
-    if ($@) {
-        chomp($@);
-        $response->push_header('X-Died' => $@);
+    my $err = $@;
+    delete $response->{handlers}{response_data};
+    delete $response->{handlers} unless %{$response->{handlers}};
+    if ($err) {
+        chomp($err);
+        $response->push_header('X-Died' => $err);
         $response->push_header("Client-Aborted", "die");
         return $response;
     }