kc3-lang/sys_wait

diff --git a/appveyor.yml b/appveyor.yml
index 41371fb..fa23ce1 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -1,12 +1,10 @@
 build: false
 
 environment:
-    PYTHON: "C:\\Python37"
-
     matrix:
         - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
           CMAKE_GENERATOR: "MinGW Makefiles"
-          CC: "C:\MinGW\bin\gcc.exe"
+          CC: "C:\\MinGW\\bin\\gcc.exe"
         - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
           CMAKE_GENERATOR: "Visual Studio 12 2013"
         - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015