Avoid include conflicts with headers of other libraries

Do not add .../KF5/Libkleo and .../KF5/libkleo to the target include
directories. This prevents a conflict between the new libkleo/assuan.h
header and the assuan.h header of libassuan.

src/CMakeLists.txt

@@ -132,10 +132,7 @@ install(TARGETS
     EXPORT KF5LibkleoTargets ${KF5_INSTALL_TARGETS_DEFAULT_ARGS}
 )
 
-
-
 target_include_directories(KF5Libkleo PUBLIC "$<BUILD_INTERFACE:${libkleo_SOURCE_DIR}/src;${libkleo_BINARY_DIR}/src>")
-target_include_directories(KF5Libkleo INTERFACE "$<INSTALL_INTERFACE:${KDE_INSTALL_INCLUDEDIR_KF5}/Libkleo/;${KDE_INSTALL_INCLUDEDIR_KF5}/libkleo>")
 
 ecm_generate_headers(libkleo_CamelCase_HEADERS
   HEADER_NAMES