Update AppVeyor for msvc

Author: Simsys

appveyor.yml

@@ -2,7 +2,7 @@ version: build{build}
 
 environment:
   matrix:
-    - QT: C:\Qt\5.12\msvc2015
+    - QT: C:\Qt\5.11\msvc2015
       GENERATOR: Visual Studio 14 2015
       PLATFORM: x86
     - QT: C:\Qt\5.12\msvc2015_64
@@ -14,7 +14,7 @@ clone_depth: 5
 
 install:
     - dir C:\Qt
-    - dir C:\Qt\5.12
+    - dir C:\Qt\5.11
     - set PATH=%QT%\bin\;C:\Qt\Tools\QtCreator\bin\;%PATH%
 
 before_build: