message: appveyor: fix cmake build command
diff: @@ -43,6 +43,6 @@ build_script:
  - md build
  - cd build
  - cmake -DWIN_CURL_INCLUDE_DIR:STRING=C:\\curl-7.55.1\\include -DWIN_CURL_LIB:STRING="C:\curl-7.55.1\builds\libcurl-vc14-x64-release-static-ipv6-sspi-winssl\lib\libcurl_a.lib" -G "Visual Studio 14 2015 Win64" ..
  - - cmake . --build --target=install
  + - cmake --build . --target=install
  test: off
  