Update windowsservercore Docker image

Qt is updated to 5.12.5, MSVC is updated to 2017. Qbs is updated to
1.15.0.
Docker-compose is used for managing the image. A unique tag name is used
instead of the generic windowsservercore tag to be always able to refer
to a specific version. Docker-compose is now used for managing the
image.

Change-Id: Ia5733992e7692561b1a6e74a4ac2ea3a7a01c4d8
Reviewed-by: Richard Weickelt <richard@weickelt.de>
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

1 files changed, 0 insertions, 1 deletions

diff --git a/docker/docker.qbs b/docker/docker.qbs
index 5adc277e4..752c61d3b 100644
--- a/docker/docker.qbs
+++ b/docker/docker.qbs
@@ -29,7 +29,6 @@ Project {
 
         files: [
             "windowsservercore/Dockerfile",
-            "windowsservercore/build-qt.bat",
         ]
     }
 }