azure: compile one Windows platform with the WinHTTP SHA1 backend

We currently have no job that compiles libgit2 with the WinHTTP backend
for SHA1. Due to this, a compile error has been introduced and not
noticed for several months. Change the x86 MSVC job to use the HTTPS
backend for SHA1. The x86 job was chosen with no particular reason.

azure-pipelines.yml

@@ -90,7 +90,7 @@ jobs:
   - template: azure-pipelines/powershell.yml
     parameters:
       environmentVariables:
-        CMAKE_OPTIONS: -DMSVC_CRTDBG=ON -G"Visual Studio 12 2013" -DDEPRECATE_HARD=ON
+        CMAKE_OPTIONS: -DMSVC_CRTDBG=ON -G"Visual Studio 12 2013" -DDEPRECATE_HARD=ON -DUSE_SHA1=HTTPS
 
 - job: windows_mingw_amd64
   displayName: 'Windows (amd64; MinGW)'

azure-pipelines/nightly.yml

@@ -92,7 +92,7 @@ jobs:
   - template: powershell.yml
     parameters:
       environmentVariables:
-        CMAKE_OPTIONS: -DMSVC_CRTDBG=ON -G"Visual Studio 12 2013" -DDEPRECATE_HARD=ON
+        CMAKE_OPTIONS: -DMSVC_CRTDBG=ON -G"Visual Studio 12 2013" -DDEPRECATE_HARD=ON -DUSE_SHA1=HTTPS
         RUN_INVASIVE_TESTS: true
 
 - job: windows_mingw_amd64