Install headers required by kfind.

diff --git a/lib/konq/src/CMakeLists.txt b/lib/konq/src/CMakeLists.txt
index 1186f32..9c05b9f 100644
--- a/lib/konq/src/CMakeLists.txt
+++ b/lib/konq/src/CMakeLists.txt
@@ -60,6 +60,7 @@ install(FILES
     konq_historyentry.h
     konq_historyprovider.h
     konq_operations.h
+    konq_popupmenu.h
     konq_popupmenuplugin.h
     kversioncontrolplugin.h
     kversioncontrolplugin2.h