Windows: cast between incompatible function types in address.c
```
bash.exe : ../src/common/address.c: In function 'get_interface_addresses_win32':
At line:2 char:5
+ & $commandPath $args 2>&1
+ ~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (../src/common/a...dresses_win32'::String) [], RemoteException
+ FullyQualifiedErrorId : NativeCommandError
../src/common/address.c:1499:14: error: cast between incompatible function types from 'FARPROC' {aka 'long long int (*)()'} to 'ULONG (*)(ULONG, ULONG, void *, IP_ADAPTER_ADDRESSES_XP *, ULONG *)' {aka 'long unsigned int
(*)(long unsigned int, long unsigned int, void *, struct _IP_ADAPTER_ADDRESSES_XP *, long unsigned int *)'} [-Werror=cast-function-type]
if (!(fn = (GetAdaptersAddresses_fn_t)
^
```
https://ci.appveyor.com/project/teor2345/tor/build/1.0.152/job/g7dxnnck0r3p66n9#L1093
issue