Switch to appveyor VS2019 image to match cutter-deps (#2184)

* Force gyp to generate vs2017 project and then upgrade it to vs2019 because version used by breakpad doesn't recognize vs2019.

.appveyor.yml

@@ -1,5 +1,5 @@
 version: '1.10.3-pre2-git-{build}'
-image: 'Visual Studio 2017'
+image: 'Visual Studio 2019'
 clone_depth: 1
 
 # Build configuration
@@ -9,7 +9,7 @@ configuration:
 # Environment
 environment:
   NINJA_URL: https://github.com/ninja-build/ninja/releases/download/v1.9.0/ninja-win.zip
-  VSVARSALLPATH: 'C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\VC\Auxiliary\Build\vcvarsall.bat'
+  VSVARSALLPATH: 'C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build\vcvarsall.bat'
   QTPATH: 'cutter-deps\qt'
   USE_APPVEYOR_QT: 'false'
   matrix:

scripts/prepare_breakpad.bat

@@ -24,7 +24,9 @@ DEL %CD%\build_all.vcxproj
 COPY %ROOT_DIR%\scripts\breakpad_client.gyp %CD%
 
 CD %ROOT_DIR%\src\breakpad\src\src
+SET GYP_MSVS_VERSION=2017
 powershell -Command "tools\gyp\gyp.bat --no-circular-check client\windows\breakpad_client.gyp -Dwin_release_RuntimeLibrary=2 -Dwin_debug_RuntimeLibrary=2  -Dplatform=%ARCH% -Dconfiguration=release"
+devenv client\windows\breakpad_client.sln /upgrade
 
 set PATH=%BUFF_PATH%
 msbuild /m %CD%\client\windows\breakpad_client.sln /p:Configuration=release /p:Platform=%ARCH% || exit /b 1