Add multicast.c to hamlib build

https://github.com/Hamlib/Hamlib/issues/695

src/Makefile.am

@@ -10,7 +10,7 @@ RIGSRC = hamlibdatetime.h rig.c serial.c serial.h misc.c misc.h register.c regis
    	network.c network.h cm108.c cm108.h gpio.c gpio.h idx_builtin.h token.h \
    	par_nt.h microham.c microham.h amplifier.c amp_reg.c amp_conf.c \
    	amp_conf.h amp_settings.c extamp.c sleep.c sleep.h sprintflst.c \
-   	sprintflst.h cache.c cache.h snapshot_data.c snapshot_data.h multicast.h
+   	sprintflst.h cache.c cache.h snapshot_data.c snapshot_data.h multicast.c multicast.h
 
 if VERSIONDLL
 RIGSRC +=	\

src/multicast.c

@@ -367,7 +367,7 @@ int multicast_send(RIG *rig, unsigned char *msg, int msglen)
     return num_bytes;
 }
 
-#define TEST
+//#define TEST
 #ifdef TEST
 int main(int argc, char *argv[])
 {

tests/multicastclient.c

@@ -46,7 +46,7 @@ int main()
     // Set the SO_REUSEADDR option to allow multiple processes to use the same address
     int optval = 1;
 
-    if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &optval,
+    if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (char*)&optval,
                    sizeof(optval)) < 0)
     {
         //rig_debug(RIG_DEBUG_ERR, "%s: setsockopt: %s\n", __func__, strerror(errno));