bump libopenmpt to v0.8.3

[notspiff]

Seems to build everywhere now, thanks to rechi for help

[garbear]

Jenkins fails for ios and tvos?

-- [download 100% complete]
-- verifying file...
       file='/Users/Shared/xbmc-depends/tarballs/libopenmpt-0.8.2+release.autotools.tar.gz'
-- SHA256 hash of
    /Users/Shared/xbmc-depends/tarballs/libopenmpt-0.8.2+release.autotools.tar.gz
  does not match expected value
    expected: '844e4ff98dbd9942bbe4a1048226f91f8bc5b460b7bec6489e67cedb3e0aac37'
      actual: 'e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855'
-- Hash mismatch, removing...
CMake Error at openmpt-stamp/download-openmpt.cmake:163 (message):
  Each download failed!

[notspiff]

i have no idea about the hash mismatches, it seems random which platform complains about it from build to build.

[garbear]

Probably an error response from the https://lib.openmpt.org server. Can you use another?

[notspiff]

no, there is no error response, download completes fine, it just hashes wrong. it's all green now though, so..

[garbear]

Released 22.0.2