Removed the vi format comments from the source

Vim users can use the [editorconfig plugin](https://github.com/editorconfig/editorconfig-vim) to automatically set tab spacing for the SDL coding style.

Fixes https://github.com/libsdl-org/SDL/issues/6903

src/misc/haiku/SDL_sysurl.cc

@@ -30,6 +30,3 @@ SDL_SYS_OpenURL(const char *url)
     const status_t rc = burl.OpenWithPreferredApplication(false);
     return (rc == B_NO_ERROR) ? 0 : SDL_SetError("URL open failed (err=%d)", (int) rc);
 }
-
-/* vi: set ts=4 sw=4 expandtab: */
-