CI: Enable appveyor FTP upload

- Don't use alternative FTP library
- active_mode: false is the default so not needed
3 jobs for master in 3 minutes and 26 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Test
passed #15315
run-appdata

00:00:06

passed #15314
run-tests

00:03:08

 
  Build
passed #15316
run-build

00:00:12