Appveyor: Link vcpkg DLLs except for readline

.appveyor.yml

@@ -49,7 +49,6 @@ for:
     - .\bootstrap-vcpkg.bat
     - cd %APPVEYOR_BUILD_FOLDER%
     - vcpkg --triplet %Platform%-windows install libffi libyaml readline zlib
-    - set PATH=c:\Tools\vcpkg\installed\%Platform%-windows\bin;%PATH%
     - CALL SET vcvars=%%^VS%VS%COMNTOOLS^%%..\..\VC\vcvarsall.bat
     - SET vcvars
     - '"%vcvars%" %Platform:x64=amd64%'
@@ -73,6 +72,9 @@ for:
     - if not exist %ZLIB_ZIP% curl -fsSL -o %ZLIB_ZIP% --retry 10 https://zlib.net/zlib%zlib_version:.=%.zip
     - 7z x -aos -o%APPVEYOR_BUILD_FOLDER%\ext\zlib %ZLIB_ZIP%
     - for %%I in (%OPENSSL_DIR%\*.dll) do mklink /h \usr\local\bin\%%~nxI %%I
+    - for %%I in (c:\Tools\vcpkg\installed\%Platform%-windows\bin\*.dll) do (
+        if not %%~nI == readline mklink \usr\local\bin\%%~nxI %%I
+      )
     - attrib +r /s /d
     - mkdir %Platform%-mswin_%vs%
   build_script: