package/ci: use a correctly prefixed Corrade CMake option.

package/ci/appveyor.yml

@@ -54,7 +54,7 @@ environment:
   - TARGET: desktop
     COMPILER: msvc
     # Same reasoning as in Corrade for /EHsc
-    COMPILER_EXTRA: -DCMAKE_CXX_FLAGS="/permissive- /EHsc" -DMSVC_COMPATIBILITY=OFF
+    COMPILER_EXTRA: -DCMAKE_CXX_FLAGS="/permissive- /EHsc" -DCORRADE_MSVC_COMPATIBILITY=OFF
     APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
     APPVEYOR_JOB_NAME: windows-conforming-msvc2019
     PYTHON: 7
@@ -62,7 +62,7 @@ environment:
   - TARGET: desktop
     COMPILER: msvc
     # Not playing with fire and using /EHsc on 2022 as well
-    COMPILER_EXTRA: -DCMAKE_CXX_FLAGS="/permissive- /EHsc" -DMSVC_COMPATIBILITY=OFF
+    COMPILER_EXTRA: -DCMAKE_CXX_FLAGS="/permissive- /EHsc" -DCORRADE_MSVC_COMPATIBILITY=OFF
     APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2022
     APPVEYOR_JOB_NAME: windows-conforming-msvc2022
     PYTHON: 7