traymon: cmake: only check for Qt4 if Qt5 is not found

This fixes problems that exist if both Qt versions are installed.

If Qt5 is available, it is used. Only if it is not available,
Qt4 is tried.

core/src/qt-tray-monitor/CMakeLists.txt

@@ -29,9 +29,17 @@ set(CMAKE_INCLUDE_CURRENT_DIR ON)
 set(CMAKE_AUTOUIC ON)
 set(CMAKE_AUTORCC ON)
 
-find_package(Qt4)
-
 find_package(Qt5 COMPONENTS Core Widgets)
+IF(Qt5Widgets_FOUND)
+  message(STATUS "Found QT5Widgets")
+ELSE()
+  message(STATUS "QT5Widgets NOT found, checking for Qt4 ...")
+  find_package(Qt4)
+  IF (NOT Qt4_FOUND)
+    message(FATAL_ERROR "Both Qt5 and Qt4 not found, cannot build tray-monitor")
+  ENDIF()
+ENDIF()
+
 
 IF(HAVE_WIN32)
    include_directories(