Fix build error with Android NDK

src/shrpx_memcached_connection.cc

@@ -27,6 +27,8 @@
 #include <limits.h>
 #include <sys/uio.h>
 
+#include <cerrno>
+
 #include "shrpx_memcached_request.h"
 #include "shrpx_memcached_result.h"
 #include "shrpx_config.h"

src/timegm.c

@@ -84,5 +84,5 @@ time_t nghttp2_timegm_without_yday(struct tm *tm) {
   }
 #endif /* SIZEOF_TIME_T == 4 */
 
-  return t;
+  return (time_t)t;
 }