unittests: don't register app layer test

Some tests are already registered via the function
AppLayerParserRegisterProtocolUnittests. So we don't need to
egister them during runmode initialization.
suricata: RunUnittests now return void

RunUnittests function is now a terminal function (calling exit
before leaving).
magic: disable tests depending on magic version

Some tests depend on specific results by specific magic versions.
Disable these.