Don't error out when DEPENDENCY_ROOT is not set

CMakeModules/CPackConfiguration.cmake

@@ -45,7 +45,7 @@ include(CPack)
 
 cpack_add_component(Core DISPLAY_NAME "Plex Media Player" DESCRIPTION "Plex Media Player (Core Application)" REQUIRED)
 
-if(WIN32)
+if(WIN32 AND DEFINED DEPENDENCY_ROOT)
   FILE(TO_CMAKE_PATH ${DEPENDENCY_ROOT} tmp)
   install(FILES ${tmp}/bin/mpv-1.dll DESTINATION .)
   install(FILES ${tmp}/lib/SDL2.dll DESTINATION .)
@@ -62,4 +62,4 @@ if(WIN32)
   message(STATUS configure IFW)
   include(CPackIFW)
   cpack_ifw_configure_component(Core PRIORITY 1 SCRIPT ${CMAKE_SOURCE_DIR}/bundle/win/shortcut.qs)
-endif(WIN32)
+endif(WIN32 AND DEFINED DEPENDENCY_ROOT)