Bug#754982: FTBFS on kfreebsd with new miniupnpc

[Emilio Pozuelo Monfort <pochu@debian.org>]

Package: transmission
Version: 2.82-1.1
Severity: serious
Control: block 749560 with -1

Your package failed to build on kfreebsd:

miniupnpc.c:115:8: warning: no previous declaration for 'simpleUPnPcommand2' [-Wmissing-declarations]
 char * simpleUPnPcommand2(int s, const char * url, const char * service,
        ^
miniupnpc.c: In function 'upnpDiscover':
miniupnpc.c:515:21: error: storage size of 'reqn' isn't known
     struct ip_mreqn reqn; /* only defined with -D_BSD_SOURCE or -D_GNU_SOURCE */
                     ^
miniupnpc.c:516:29: error: invalid application of 'sizeof' to incomplete type 'struct ip_mreqn'
     memset(&reqn, 0, sizeof(struct ip_mreqn));
                             ^
miniupnpc.c:515:21: warning: unused variable 'reqn' [-Wunused-variable]
     struct ip_mreqn reqn; /* only defined with -D_BSD_SOURCE or -D_GNU_SOURCE */
                     ^
make[5]: *** [miniupnpc.o] Error 1

https://buildd.debian.org/status/logs.php?pkg=transmission&ver=2.82-1.1%2Bb1

Emilio