The server name ending with .jar has several drawbacks:
 - meson requires the jar executable to attempt to modify it:
     <https://github.com/Genymobile/scrcpy/issues/404#issuecomment-456065923>
     <https://github.com/mesonbuild/meson/issues/4844>
 - meson warns during "ninja install"
     <https://github.com/Genymobile/scrcpy/issues/458>
 - some users try to execute it on the computer as a java executable

Removing the extension solves all these problems.