Fixes issue with steam compile (#97)

Broken in: 8d37f6e (monster pathing)
Issue located through bisect.

Author: LiquidityC

CMakeLists.txt

@@ -182,11 +182,6 @@ set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -DDEBUG")
 if (STEAM)
 	set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -DSTEAM_BUILD")
 	set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -DSTEAM_BUILD")
-	set(STEAM_SOURCES
-		src/steam/steamworks_api_wrapper.c
-		)
-else ()
-	set(STEAM_SOURCES "")
 endif ()
 
 if (MINGW)

src/CMakeLists.txt

@@ -1,7 +1,6 @@
 file(GLOB SOURCE_FILES CONFIGURE_DEPENDS *.c)
+target_sources(${PROJECT_NAME} PRIVATE ${SOURCE_FILES})
 
 if (STEAM)
-	file(GLOB SOURCE_FILES CONFIGURE_DEPENDS steam/*.c)
+	target_sources(${PROJECT_NAME} PRIVATE steam/steamworks_api_wrapper.c)
 endif ()
-
-target_sources(${PROJECT_NAME} PRIVATE ${SOURCE_FILES})