CMakeLists: only set the WIN32 property in release mode.

I can't find the setting that allows CLion to capture stdout when
running normally anymore, so this is the next best thing.

src/CMakeLists.txt

@@ -43,7 +43,7 @@ if(CORRADE_TARGET_WINDOWS)
     set(SAVETOOL_RC_FILE resource.rc)
 endif()
 
-add_executable(MassBuilderSaveTool WIN32
+add_executable(MassBuilderSaveTool
     main.cpp
     SaveTool/SaveTool.h
     SaveTool/SaveTool.cpp
@@ -109,6 +109,10 @@ add_executable(MassBuilderSaveTool WIN32
     ${Assets}
 )
 
+if(CORRADE_TARGET_WINDOWS)
+    set_target_properties(${PROJECT_NAME} PROPERTIES WIN32_EXECUTABLE $<CONFIG:Release>)
+endif()
+
 if(CMAKE_BUILD_TYPE STREQUAL Debug)
     target_compile_definitions(Logger PRIVATE SAVETOOL_DEBUG_BUILD)
     target_compile_definitions(MassBuilderSaveTool PRIVATE SAVETOOL_DEBUG_BUILD)