Allow running build-msvc.ps1 from anywhere

Signed-off-by: Samuli Seppänen <[email protected]>

build-msvc.ps1

@@ -5,13 +5,19 @@ $CWD = Get-Location
 $CMAKE="C:\Program Files\CMake\bin\cmake.exe"
 $CMAKE_TOOLCHAIN_FILE="C:\users\vagrant\buildbot\windows-server-2019-static-msbuild\vcpkg\scripts\buildsystems\vcpkg.cmake"
 
+# Enable running this script from anywhere
+cd $PSScriptRoot
+
 # Architecture names taken from here:
 #
 # https://docs.microsoft.com/en-us/cpp/build/cmake-presets-vs?view=msvc-160
 "x64", "arm64", "Win32" | ForEach  {
 	$platform = $_
     Write-Host "Building openvpn-gui ${platform}"
-    mkdir build_$platform
+    if ( ( Test-Path "build_${platform}" ) -eq $False )
+	{
+        mkdir build_$platform
+	}
     cd build_$platform
     & "$CMAKE" -A $platform -DCMAKE_TOOLCHAIN_FILE="$CMAKE_TOOLCHAIN_FILE" ..
     & "$CMAKE" --build . --config Release