Reduce vs2015/2017 configurations

    * azure-pipelines.yml:

Author: jwillemsen

azure-pipelines.yml

@@ -79,12 +79,6 @@ jobs:
     vmImage: vs2017-win2016
   strategy:
     matrix:
-      Debug64:
-        BuildPlatform: x64
-        BuildConfiguration: Debug
-        vcpkgarch: x64-windows
-        vcpkglibdir: debug\lib
-        vcpkgpackages: openssl xerces-c
       Release64:
         BuildPlatform: x64
         BuildConfiguration: Release
@@ -131,11 +125,6 @@ jobs:
     vmImage: vs2015-win2012r2
   strategy:
     matrix:
-      Debug64:
-        BuildPlatform: x64
-        BuildConfiguration: Debug
-        vcpkgarch: x64-windows
-        vcpkglibdir: debug\lib
       Release64:
         BuildPlatform: x64
         BuildConfiguration: Release