CMake: fix comment about why headers are treated as source

It's not to make dependency checks work (they'll work regardless). The
usual reason to add header files is so they get included in generated
IDE projects (like for Visual Studio).

Author: ligfx

CMakeLists.txt

@@ -21,9 +21,6 @@ src/ActiveSocket.cpp
 src/PassiveSocket.cpp
 )
 
-# append to sources so that dependency checks work on headers
-LIST(APPEND CLSOCKET_SOURCES ${CLSOCKET_HEADERS})
-
 OPTION(BUILD_SHARED_LIBS "Build libs as shared" ON)
 if(DEFINED CLSOCKET_SHARED)
     message(FATAL_ERROR "The CLSOCKET_SHARED option is deprecated, instead use BUILD_SHARED_LIBS.")
@@ -33,7 +30,8 @@ if(DEFINED CLSOCKET_DEP_ONLY)
 endif()
 
 # make the lib
-ADD_LIBRARY(clsocket ${CLSOCKET_SOURCES})
+# add headers so that they appear in IDEs
+ADD_LIBRARY(clsocket ${CLSOCKET_SOURCES} ${CLSOCKET_HEADERS})
 target_include_directories(clsocket PUBLIC src)
 if(WIN32)
     add_definitions(-D_WINSOCK_DEPRECATED_NO_WARNINGS)