Many parsing and formatting C functions like strtof() and asprintf() are
locale-dependent. Forcing a C locale just for the conversions in a way
that works on all platforms is a mess.
In practice, this is not a problem, scrcpy always uses the C locale,
because it never calls:
setlocale(LC_ALL, "");
But the max-fps option should not depend on the locale configuration
anyway.
Since the value is parsed by the client in Java anyway, just forward the
string value as is.