fix deploy script

Author: skvark

appveyor.yml

@@ -108,5 +108,5 @@ artifacts:
   name: wheels
 
 deploy_script:
-    - cmd: IF "%APPVEYOR_REPO_TAG%" == "true" ( twine -u %USER% -p %PASS% -r pypitest dist/*" ) else ( echo "Tag not set, deployment skipped." )
+- if "%APPVEYOR_REPO_TAG%"=="true" (twine -u %USER% -p %PASS% -r pypitest dist/*) else (echo "Tag not set, deployment skipped.")