Fix unit test

Author: Crayon2000

tests/message.cpp

@@ -181,15 +181,15 @@ TEST_CASE("message equality non equal lhs empty", "[message]")
 
 TEST_CASE("message rebuild with size", "[message]")
 {
-    zmq::message_t msg();
+    zmq::message_t msg;
     msg.rebuild(5)
     CHECK(msg.size() == 5);
 }
 
 #if defined(ZMQ_CPP11) && !defined(ZMQ_CPP11_PARTIAL)
 TEST_CASE("message rebuild with string literal", "[message]")
 {
-    zmq::message_t hi_msg();
+    zmq::message_t hi_msg;
     hi_msg.rebuild("Hi")
     REQUIRE(2u == hi_msg.size());
     CHECK(0 == memcmp(data, hi_msg.data(), 2));
@@ -200,7 +200,7 @@ TEST_CASE("message rebuild with strings", "[message]")
     SECTION("string")
     {
         const std::string hi(data);
-        zmq::message_t hi_msg();
+        zmq::message_t hi_msg;
         hi_msg.rebuild(hi)
         CHECK(2u == hi_msg.size());
         CHECK(0 == memcmp(data, hi_msg.data(), 2));
@@ -209,7 +209,7 @@ TEST_CASE("message rebuild with strings", "[message]")
     SECTION("string_view")
     {
         const std::string_view hi(data);
-        zmq::message_t hi_msg();
+        zmq::message_t hi_msg;
         hi_msg.rebuild(hi)
         CHECK(2u == hi_msg.size());
         CHECK(0 == memcmp(data, hi_msg.data(), 2));