Add missing include for system header file

Only affects externally built plugins.

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

svc.h

@@ -27,6 +27,7 @@
 
 #include <errno.h>
 #include <string.h>		/* strerror() */
+#include <sys/ipc.h>		/* IPC_CREAT */
 #include <sys/shm.h>		/* shmat() */
 #include <sys/types.h>		/* pid_t */