Chang #error to #warning for the 32-bit environment check except 32-bit Windows

Author: yhirose

README.md

@@ -871,7 +871,7 @@ auto res = cli.Post(
 httplib::Client cli(url, port);
 
 // prints: 0 / 000 bytes => 50% complete
-auto res = cli.Get("/", [](uint64_t len, uint64_t total) {
+auto res = cli.Get("/", [](size_t len, size_t total) {
   printf("%lld / %lld bytes => %d%% complete\n",
     len, total,
     (int)(len*100/total));

httplib.h

@@ -18,10 +18,10 @@
 #error                                                                         \
     "cpp-httplib doesn't support 32-bit Windows. Please use a 64-bit compiler."
 #elif defined(__SIZEOF_POINTER__) && __SIZEOF_POINTER__ < 8
-#error                                                                         \
+#warning                                                                       \
     "cpp-httplib doesn't support 32-bit platforms. Please use a 64-bit compiler."
 #elif defined(__SIZEOF_SIZE_T__) && __SIZEOF_SIZE_T__ < 8
-#error                                                                         \
+#warning                                                                       \
     "cpp-httplib doesn't support platforms where size_t is less than 64 bits."
 #endif