appveyor.yml: reorder jobs

to reduce time to get all green. As we have 3 parallelism on AppVeyor,
running the slow msys2 job first doesn't have significant impact on
job priorities, but at the same time this would reduce the time that
only msys2 is running alone at last.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65052 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

appveyor.yml

@@ -7,14 +7,14 @@ environment:
   ruby_version: "24-%Platform%"
   zlib_version: "1.2.11"
   matrix:
+    - build: msys2
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
     - build: vs
       vs: 120
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2013
     - build: vs
       vs: 140
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
-    - build: msys2
-      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
 notifications:
   - provider: Webhook
     url: