[AppVeyor] Haxe 3.4 is now rc2

appveyor.yml

@@ -20,7 +20,7 @@ install:
   - appveyor DownloadFile http://hxbuilds.s3-website-us-east-1.amazonaws.com/builds/haxe/windows/haxe_latest.tar.gz
   - 7z x "haxe_latest.tar.gz" -so | 7z x -aoa -si -ttar
   - RefreshEnv
-  - set PATH=%APPVEYOR_BUILD_FOLDER%\haxe-3.4.0-rc1;%PATH%
+  - set PATH=%APPVEYOR_BUILD_FOLDER%\haxe-3.4.0-rc2;%PATH%
   - neko -version
   - haxe -version