Add cctype header (yhirose#656)

mi01 · web-flow · commit b8cf739d275d · 2020-09-16T16:32:49.000-04:00
diff --git a/httplib.h b/httplib.h
@@ -196,6 +196,7 @@ using socket_t = int;
 #include <string>
 #include <sys/stat.h>
 #include <thread>
+#include <cctype>
 
 #ifdef CPPHTTPLIB_OPENSSL_SUPPORT
 #include <openssl/err.h>
