test: fix GetRangeWithMaxLongLength on 32 bit machines (#1867)

The test used the hardcoded long value for 64 bit machines even on 32
bit ones, leading to test failures. With this patch the max long length
is obtained using std::numeric_limits<long>::max(). Thanks to q2a3z for
the hint!

Fixes: https://github.com/yhirose/cpp-httplib/issues/1795

test/test.cc

@@ -6,6 +6,7 @@
 #include <atomic>
 #include <chrono>
 #include <future>
+#include <limits>
 #include <memory>
 #include <sstream>
 #include <stdexcept>
@@ -3474,7 +3475,7 @@ TEST_F(ServerTest, GetStreamedWithRangeError) {
 
 TEST_F(ServerTest, GetRangeWithMaxLongLength) {
   auto res =
-      cli_.Get("/with-range", {{"Range", "bytes=0-9223372036854775807"}});
+      cli_.Get("/with-range", {{"Range", "bytes=0-" + std::to_string(std::numeric_limits<long>::max())}});
   EXPECT_EQ(StatusCode::RangeNotSatisfiable_416, res->status);
   EXPECT_EQ("0", res->get_header_value("Content-Length"));
   EXPECT_EQ(false, res->has_header("Content-Range"));