cmake: use `list(APPEND ...)` where missing

Cherry-picked from #20407

Closes #20522

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 66639198517ebc2f905eb6b2b6b1a5c0417d0dcd..14dcc955dedaf1b5d01d6ea22e91cf95b0111e8a 100644 (file)
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1920,7 +1920,7 @@ endif()
 macro(curl_add_if _label)
   # Needs to be a macro to allow this indirection
   if(${ARGN})
-    set(_items ${_items} "${_label}")
+    list(APPEND _items "${_label}")
   endif()
 endmacro()