Fix finding and including for SDL2
diff --git a/CMakeLists.txt b/CMakeLists.txt
index e346c49..0461e8a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -26,6 +26,7 @@ set(CMAKE_INSTALL_DATADIR ${CMAKE_INSTALL_DATAROOTDIR}/crossfire-client)
 find_program(GLIB_COMPILE_RESOURCES NAMES glib-compile-resources)
 find_package(PkgConfig REQUIRED)
 pkg_check_modules(GTK gtk+-2.0 gio-2.0 REQUIRED)
+pkg_check_modules(SDL sdl2 REQUIRED)
 find_package(PNG REQUIRED)
 find_package(Perl REQUIRED)
 find_package(Vala REQUIRED)
diff --git a/gtk-v2/src/CMakeLists.txt b/gtk-v2/src/CMakeLists.txt
index f9d3b30..a8ae5f2 100644
--- a/gtk-v2/src/CMakeLists.txt
+++ b/gtk-v2/src/CMakeLists.txt
@@ -45,7 +45,7 @@ target_include_directories(crossfire-client-gtk2
             ${GTK_INCLUDE_DIRS}
             ${PNG_INCLUDE_DIRS}
             ${SDLMIXER_INCLUDE_DIRS}
-            ${SDL_INCLUDE_DIR}
+	    ${SDL_INCLUDE_DIRS}
 )
 
 target_link_libraries(crossfire-client-gtk2 cfclient