fix windows build scripts

.appveyor.yml

@@ -7,7 +7,6 @@ clone_folder: C:\rssguard
 environment:
   QTDIR: 'C:\Qt\5.12\msvc2017_64'
   QMAKESPEC: win32-msvc
-  COMPILERBAT: '"C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\VC\Auxiliary\Build\vcvars64.bat"'
   access_token:
     secure: oR2iY1h+Z5AF4t3yP1mxNW7HL8qhPm8y4Uupp4b03QSC7puVrkkCaO1E1NQA9q9K
   matrix:

resources/scripts/.appveyor-build-win.ps1

@@ -3,6 +3,9 @@ $old_pwd=$pwd.Path
 ls
 echo "Qmake args are: '$env:qmake_args'."
 
+# Setup env path with qmake.
+$env:PATH = "$env:QTDIR\bin;" + $env:PATH
+
 mkdir "rssguard-build"
 cd "rssguard-build"
 qmake.exe ..\build.pro "$env:qmake_args"