[PATCH] Install translations

[glixx]

diff -Nru a/CMakeLists.txt b/CMakeLists.txt
--- a/CMakeLists.txt	2018-09-06 19:53:47.000000000 +0200
+++ b/CMakeLists.txt	2019-01-31 06:55:36.549679806 +0100
@@ -27,6 +27,8 @@
 set(CMAKE_AUTOUIC ON)
 
 add_subdirectory(src)
-add_subdirectory(po)
+if (IS_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/po")
+    ki18n_install(po)
+endif()
 
 feature_summary(WHAT ALL FATAL_ON_MISSING_REQUIRED_PACKAGES)