fix: portable includes for FreeBSD and libstdc++

Author: blburns

src/simple-httpd/access_control.cpp

@@ -16,6 +16,8 @@
 #include <ws2tcpip.h>
 #else
 #include <arpa/inet.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
 #endif
 
 namespace simple_httpd {

src/simple-httpd/server.cpp

@@ -29,6 +29,7 @@
 #include <algorithm>
 #include <atomic>
 #include <chrono>
+#include <condition_variable>
 #include <ctime>
 #include <fstream>
 #include <memory>