Fix blank commit information for AppVeyor

appveyor.yml

@@ -12,9 +12,6 @@ environment:
   OPENRCT2_ORG_TOKEN:
     secure: leQX3xCQpmBLGuMqrxjFlzexDt96ypNRMM5TTRVHbGE8PwVg9crgeykLc2BIZU6HDHveJCHqh2cGMdHtHYJYcw==
   BUILD_SERVER: AppVeyor
-  GIT_TAG: $(APPVEYOR_REPO_TAG_NAME)
-  GIT_BRANCH: $(APPVEYOR_REPO_BRANCH)
-  GIT_COMMIT_SHA1: $(APPVEYOR_REPO_COMMIT)
   PATH: $(PATH);C:\Program Files (x86)\Windows Kits\10\bin\x86
 install:
 - ps: >-

scripts/ps/appveyor_install.ps1

@@ -49,3 +49,7 @@ else
     # Don't build the NSIS installer for non-uploaded builds
     ${env:NO_NSIS} = "true"
 }
+
+$env:GIT_TAG            = $env:APPVEYOR_REPO_TAG_NAME
+$env:GIT_BRANCH         = $env:APPVEYOR_REPO_BRANCH
+$env:GIT_COMMIT_SHA1    = $env:APPVEYOR_REPO_COMMIT