Update reactiveplusplus to v2.1.1 (#3729)

packages/r/reactiveplusplus/xmake.lua

@@ -7,7 +7,9 @@ package("reactiveplusplus")
     add_urls("https://github.com/victimsnino/ReactivePlusPlus/archive/refs/tags/$(version).tar.gz",
              "https://github.com/victimsnino/ReactivePlusPlus.git")
 
-    add_versions("v0.2.3", "9542419f8d7da98126ba2c6ae08fab287b4b3798d89cf75ed9bed2a9e3ec1678")
+    add_versions("v2.1.1", "0b962478d7c973a1f74062ce7f8d24c2fdcd2733031b1f014e65d252d59ebe6a",
+                 "v2.1.0", "d84a194ef96b92201ea574f81780837c95e8956bbad09b3dc2dc5cef7c2eef98",
+                 "v0.2.3", "9542419f8d7da98126ba2c6ae08fab287b4b3798d89cf75ed9bed2a9e3ec1678")
 
     add_deps("cmake")
     add_includedirs("include/rpp")
@@ -18,7 +20,7 @@ package("reactiveplusplus")
 
     on_test(function (package)
         local snippets
-        if package:version():le("0.2.3") then
+        if package:version() and package:version():le("0.2.3") then
             snippets = [[
                 void test() {
                     rpp::source::just(0, 1, 2, 3, 4, 5, 6, 7, 8, 9)