Accept a range of ports to listen to, so that it does not fail if
another instance of scrcpy is currently starting.
The range can be passed via the command line:
scrcpy -p 27183:27186
scrcpy -p 27183 # implicitly 27183:27183, as before
The default is 27183:27199.
Closes#951 <https://github.com/Genymobile/scrcpy/issues/951>
A proper solution could be to use "long long" instead (guaranteed to be
at least 64 bits), but it adds its own problems (e.g. "%lld" is not
supported as a printf format on all platforms).
In practice, we don't need such high values, so keep it simple.
Fixes#995 <https://github.com/Genymobile/scrcpy/issues/995>
